ILLINOIS  STATE  GEOLOGICAL  SURVEY 


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J 


STATE  OF  ILLINOIS 
DEPARTMENT  OF  REGISTRATION  AND  EDUCATION 

DIVISION  OF  THE 
STATE  GEOLOGICAL  SURVEY 

M.    M.  LEIGHTON,  Chief 


BULLETIN  NO.  45 


STRUCTURAL  RECONNAISSANCE  OF  THE 

MISSISSIPPI  VALLEY  AREA  FROM 

OLD  MONROE,  MISSOURI,  TO 

NAUVOO,  ILLINOIS 


BY 

FRANK  KREY 


In  co-operation  with  Missouri 
Bureau  of  Geology  and  Mines 


PRINTED  BY  AUTHORITY  OF  THE  STATE  OF  ILLINOIS 


URBANA,  ILLINOIS 
1924 


STATE  OF  ILLINOIS 

DEPARTMENT  OF  REGISTRATION  AND  EDUCATION 

DIVISION  OF  THE 
STATE  GEOLOGICAL  SURVEY 

M.  M.  LEIGHTON,    Chief 


BULLETIN  NO.  45 ' 

STRUCTURAL  RECONNAISSANCE  OF  THE  MISSISSIPPI 

VALLEY  AREA  FROM  OLD  MONROE,  MISSOURI, 

TO  NAUVOO,  ILLINOIS 


BY 
FRANK  KREY 


In  co-operation  with  Missouri 
Bureau  of  Geology  and  Mines 

PRINTED  BY  AUTHORITY  OF  THE  STATE  OF  ILLINOIS 


URBANA,  ILLINOIS 
1924 


STATE  OF  ILLINOIS 

DEPARTMENT  OF  REGISTRATION  AND  EDUCATION 

DIVISION  OF  THE 
STATE  GEOLOGICAL  SURVEY 

M.  M.  LEIGHTON,   Chief 


Committee  of  the  Board  of  Natural  Resources 
and  Conservation 

A.  M.  Shelton,  Chairman 

Director  of  Registration  and  Education 

Kendric  C.  Babcock 

Representing  the  President' of  the  Uni- 
versity of  Illinois 

Edson  S.  Bastin 
Geologist 

(ii) 


557 

b 
no  45 

.eft 


LETTER  OF  TRANSMITTAL 


State  Geological  Survey  Division, 
February  23,  1924. 

A.  M.'Shelton,  Chairman,  and  Members  of  the  Board  of  Natural 
Resources  and  Conservation: 

Gentlemen:  I  take  pleasure  in  submitting  herewith  for 
publication  the  manuscript  on  the  "Structural  Reconnaissance 
of  the  Mississippi  Valley  Area  from  Old  Monroe,  Missouri,  to 
Nauvoo,  Illinois,'*  with  the  recommendation  that  it  be  printed 
as  Bulletin  No.  45.  In  response  to  numerous  inquiries  from  the 
oil  industry  regarding  the  geological  structure  of  the  area  men- 
tioned above,  a  co-operative  arrangement  was  made  between  the 
Missouri  Bureau  of  Geology  and  Mines  and  the  Illinois  Geological 
Survey  to  undertake  this  work.  The  successful  completion  of 
this  project  is  an  illustration  of  how  efficiently  a  geological 
problem,  which  knows  no  political  boundaries,  may  be  handled 
by  co-operative  effort.  The  work  was  assigned  to  Mr.  Frank 
Krey  who  has  brought  the  assignment  to  a  satisfactory  com- 
pletion. 

Respectfully  yours, 

M.  M.  LEIGHTON,  Chief. 
(in) 


CONTENTS 


Page 

Chapter  I: — Introduction 5 

Purpose 5 

Location  of  area 5 

Acknowledgments 5 

Genera]  statement 6 

Methods  employed 6 

Degree  of  accuracy. . . 6 

Manner  of  presentation 7 

Chapter  II. — Stratigraphy 15 

General  statement 15 

Ordovician  system 16 

Jefferson  City  group 16 

St.  Peter  group 17 

Joachim  dolomite 19 

Plattin  limestone 20 

Kimmswick  ("Trenton")  limestone 21 

Maquoketa  shale 22 

Silurian  system 24 

Alexandrian  series 24 

Edgewood  formation 24 

Sexton  Creek  limestone. 27 

Devonian  system 28 

General  statement 28 

Distribution 29 

Character  of  the  rock  and  stratigraphic  relations 29 

Mississippian  system 32 

Lower  Mississippian  sub-system 32 

Kinderhook  series 33 

Sweetland  Creek  (Grassy  Creek)  shale 33 

Louisiana  limestone 34 

Hannibal  shale 35 

Chouteau  limestone .  . 37 

Osage  series 38 

Fern  Glen  formation 38 

Burlington-Keokuk  limestone 38 

Meramec  series 39 

Warsaw-Spergen  formations 40 

St.  Louis  and  Ste.  Genevieve  formations 41 

Pennsylvanian  system 43 

Tertiary  system 44 

Quaternary  system 44 

Chapter  III. — Structure 45 

General  statement 45 

Structural  features 45 

(1) 


^  CONTENTS. 

Page 

Lincoln  fold 46 

Pittsfield-Hadley  anticline 49 

Western  Adams  County  terrace 49 

Southern  Lincoln  County  syncline 49 

Minor  structures 50 

Periods  of  deformation 50 

Chapter  IV. — Oil  possibilities 54 

Introduction 54 

Previous  exploration 54 

Review  of  the  principles  of  oil  accumulation 55 

Origin  of  oil 55 

Migration  of  oil 55 

Accumulation  of  oil 56 

Combined  effect  of  folding  and  erosion 57 

Evidences  of  oil  and  gas  within  the  region 57 

Probable  oil  horizons 58 

Factors  affecting  oil  accumulation  within  the  area 58 

Structure 58 

The  Lincoln  fold 59 

Pittsfield-Hadley  anticline 59 

Adams  County  terrace  or  monocline 59 

Minor  structures 60 

Effect  of  earlier  periods  of  folding 60 

Conclusion  concerning  structural  factors 60 

Stratigraphy 61 

Kimmswick  ("TreDton")   limestone 61 

Hoing  sand 62 

SiluriaD  limestone  and  dolomite 62 

Devonian  limestone 62 

Sweetland  Creek  (Grassy  Creek)  shale 62 

Louisiana  limestone 63 

Kinderhook  shale 63 

Higher  formations 63 

Summary  of  conclusions 63 

Chapter  V. — Records  of  wells  drilled  in  the  Mississippi   Valley  area.  ...  65 

Records  of  wells  located  in  Missouri 65 

Clark  County 65 

Lewis  County 66 

Lincoln  County 67 

Marion  County 68 

Monroe  County 70 

Pike  County 71 

Ralls  County 72 

St.  Charles  County 73 

Records  of  wells  located  in  Illinois 74 

Adams  County 74 

Calhoun  County 75 

Hancock  County 76 

Jersey  County 77 

Pike  County 78 


ILLUSTRATIONS 


Plate 

1.  Structure   map   of   area  immediately   adjoining   Mississippi    River,  In 

showing  contours  on  the  base  of  the  Burimgton  limestone pkt. 

2.  Longitudinal  sections  along  Mississippi  River,  A-A  on  the  Missouri  In 

and  B-B  on  the  Illinois  side pkt. 

3.  Three  east-west  cross-sections  in  the  north,  middle  and   south  parts  In 

of  the  area pkt. 

Facing  Page 

4.  Generalized  section  of  strata  exposed  in  the  area  covered  by  the 

report 15 

5.  A.     Steeply  dipping  Silurian  limestone  along  the   Cap-au- Gres  fault, 

6  miles  west  of  Grafton,  Jersey  County,  Illinois 24 

B.     Ledge  of  Noix  oolite  above  Maquoketa  shale  in  bed  of  creek  on 

east  side  of  road  about  5  miles  south  of  Hamburg 24 

6.  Sections  taken  at  intervals  along  Grassy  Creek,  Pike  County,  Mis- 

souri. , 25 

7.  A.     Limestone   bluff   on   east   side   of   Mississippi   River   valley,   4 

miles  south  of  Hamburg,  showing  unconformity  between  the 
Sexton  Creek  and  underlying  Bowling  Green  limestones 27 

B.     Brecciated  St.  Louis  limestone  northwest  of  St.  Patrick,  Mis- 
souri        27 

8.  East-west  section  across  northern  Ralls  County 29 

9.  A.     Unconformable  contact  between  the  Devonian  and  the  over- 

lying Louisiana  limestone  in  quarry  about  3   miles  south  ol" 
Hardin , 34 

B.     Contact  of  Hannibal  shale  and  Chouteau-Burlington  limestone 

near  Hardin  in  Calhoun  County,  Illinois 34 

10.  A.     Steeply  dipping    Burlington-Chouteau  limestone   on  the   west 

limb  of  the  Lincoln  fold  about  3  miles  northeast  of  Silex 40 

B.     Lower  Warsaw  geode  bed  near  Warsaw .% 40 

11.  A.     Possible  contact   between   Ste.   Genevieve  and  underlying  St. 

Louis  limestones    in    old    quarry    northeast    of    Spanish    Lake, 
Missouri 41 

B.     Tilted  St.  Louis  limestone  on  the  south  limb  of  Lincoln  fold, 

six  miles  west  of  Grafton,  Jersey  County,  Illinois 41 

12.  Crossvsections  to  show  the  relation  of  the  Cap-au-Gres  fault  to  the 

Lincoln  fold 47 

13.  Generalized  north-south  section  of  strata  penetrated  on  the  Mis- 

souri side  of  the  Mississippi  Valley  area 49 

(3) 


4  ILLUSTRATIONS. 

Plate  Facing  Page 

14.  Generalized  north-south  section  of  strata  penetrated  on  the  Illinois 

side  of  the  Mississippi  Valley  area 50 

15.  Section    across    Clark    County,    Missouri,    and    Hancock    County, 

Illinois . , 51 

16.  Section    across    Marion    County,    Missouri,    and    Adams    County, 

Illinois 52 

17.  Section  across  Pike  County,  Missouri,  Calhoun  and  western  Greene 

counties,  Illinois 53 

18.  Diagrams  showing  conditions  governing  oil  accumulation 57 

TABLE 

1.  List  of  index  numbers  given  on  Plate  I,  including  names  of  forma- 
tions and  elevations  of  the  tops  of  the  formations  where  con- 
tacts are  exposed 8 


STRUCTURAL  RECONNAISSANCE  OF  THE  MISSISSIPPI 

VALLEY  AREA  FROM  OLD  MONROE,  MISSOURI, 

TO  NAUVOO,  ILLINOIS 


By  Frank  Krey 
CHAPTER  I— INTRODUCTION 
Purpose 

The  work  upon  which  this  report  is  based  was  undertaken 
primarily  to  determine  the  presence  of  any  prominent  structural 
features  along  the  Mississippi  Valley  which  might  be  of  im- 
portance in  the  development  of  the  oil  resources  of  the  region. 
Careful  observations  were  made  of  the  different  rock  formations 
at  their  outcrops,  their  stratigraphic  relations,  their  variations 
in  lithologic  character  and  thickness,  and  their  distribution. 

The  field  work  was  done  in  the  summer  of  1922  from  the 
early  part  of  June  to  the  early  part  of  October,  of  which  time 
seven  weeks  were  spent  in  Missouri  and  the  remainder  in  Illinois. 
The  writer  was  assisted  in  the  field  by  Messrs.  George  Ekblaw 
and  A.  H.  Meyer,  Mr.  Ekblaw  working  from  early  June  until 
the  middle  of  September,  when  Mr.  Meyer  joined  the  writer  and 
remained  until  the  completion  of  the  field  season. 

Location  of  Area 

The  area  covered  by  this  report  includes  all  the  counties 
of  Illinois  and  Missouri  immediately  adjoining  Mississippi  River, 
beginning  with  St.  Charles  County,  Missouri,  and  Jersey  County, 
Illinois,  on  the  south,  and  extending  northward  to  the  north 
boundary  of  Missouri  and  to  the  north  boundary  of  Hancock 
County,   Illinois   (PI.   I). 

Acknowledgments 

The  writer  wishes  to  acknowledge  his  indebtedness  to  Mr. 
F.  W.  DeWolf,  formerly  Chief  of  the  Illinois  State  Geological 
Survey,  and  to  Mr.  H.  A.  Buehler,  State  Geologist  of  Missouri, 
for  many  helpful  suggestions  in  planning  the  work.     Thanks  are 

(5) 


b  MISSISSIPPI  VALLEY  AREA 

also  due  Messrs.  Geo.  Ekblaw  and  A.  H.  Meyer  for  their  faithful 
and  efficient  help  in  the  field.  Observations  along  the  Mississippi 
River  bluff  in  Missouri  between  Winfield  and  Hannibal  were 
made  by  Mr.  Ebklaw.  The  publications  of  both  the  Illinois  and 
Missouri  Surveys  have  been  freely  drawn  upon  and  different 
phases  of  the  work  have  been  discussed  with  members  of  the 
Illinois  Geological  Survey,  particularly  Drs.  T.  E.  Savage  and 
Stuarl  Welier. 

General  Statement 

It  is  obvious  that  the  structure  over  much  of  the  region, 
based  as  it  is  on  comparatively  few  rather  widely  scattered  ob- 
servations can  be  considered  suggestive  only  so  far  as  small 
local  areas  are  concerned.  The  chief  value  of  the  work,  therefore, 
is  not  its  application  to  any  one  locality,  but  rather  in  furnishing 
a  background  and  an  understanding  of  the  broad  regional  fac- 
tors without  which  the  detailed  work  in  small  areas  can  not  be 
rightly  interpreted. 

Methods  Employed 

Traverses  along  both  the  Illinois  and  Missouri  bluffs  of 
Mississippi  River,  and  detailed  observations  on  structure  and 
stratigraphy  at  least  once  every  mile,  and  generally  oftener, 
comprised  the  data  upon  which  this  report  is  based.  In  addition 
to  the  bluff  traverses,  other  east-west  traverses  were  made  across 
the  counties  at  intervals  of  from  two  to  three  miles,  but  observa- 
tions were  limited  to  only  a  few  outcrops  in  a  mile,  and  in  some 
cases  no  exposures  of  rock  were  found  for  stretches  of  several 
miles. 

Elevations  were  obtained  with  a  barometer  or  with  a  ba- 
rometer and  topographic  maps,  and  except  for  a  month  at  the 
beginning  of  the  work,  the  barometer  was  used  in  conjunction 
with  a  barograph. 

Degree  of  Accuracy 

The  accuracy  of  the  elevations  varies  somewhat  at  different 
localities.  Where  the  barometer  was  used  with  topographic 
maps  having  contour  intervals  of  twenty  feet,  the  elevations 
are  probably  all  correct  to  within  twenty  feet.  On  the  other 
hand,  where  the  barometer  was  used  without  the  barograph  and 
without  the  numerous  checks  afforded  by  a  topographic  map,  the 


INTRODUCTION  7 

elevations  may  not  be  correct  within  fifty  feet.  Fortunately  the 
only  area  worked  under  such  conditions  was  the  whole  of  Lin- 
coln County  and  the  southern  part  of  Pike  County,  Missouri. 
When  used  wun  the  barograph,  the  barometer  gave  excellent 
results  and  numerous  checks  showed  the  elevations  in  all  cases 
to  be  correct  well  within  twenty-five  feet.  Topographic  maps 
made  by  the  Mississippi  River  Commission  showing  both  bluffs, 
afforded  data  for  the  immediate  valley  of  Mississippi-  River  and 
topographic  maps  were  also  available  for  most  of  Lewis,  Clark 
and  Marion  counties,  and  parts  of  Pike,  Lincoln,  and  St.  Charles 
counties,  Missouri.  In  Illinois,  topographic  maps  were  available 
for  the  southern  tip  of  Calhoun  county  and  small  areas  in  Pike, 
Adams  and  Hancock  counties. 

Manner  of  Presentation 

In  presenting  the  results  of  this  reconnaissance,  as  much  in- 
formation as  possible  is  placed  upon  the  structure  map  of  the 
region,  (PL  I)  the  structure  being  shown  by  means  of  contours  on 
the  base  of  the  Burlington  limestone.  Outcrops  are  shown  by 
appropriate  symbols,  given  in  the  legend  of  PL  I  and  are  accom- 
panied by  index  numbers  in  each  county.  Table  1  lists  under 
counties  arranged  alphabetically  the  index  numbers  designated 
on  Plate  I,  the  formation  names,  and  the  elevation  of  the  tops  of 
the  formations  where  contacts  are  exposed.  The  major  faults 
are  indicated  on  Plate  I.  Areas  in  which  detailed  structural 
mapping  has  been  done  are  outlined  on  the  map.  Approximate 
locations  of  all  wells  known  to  reach  the  Kimmswick  ("Trenton") 
limestone  are  also  shown.  Variations  in  thickness  and  character 
of  the  formations  are  indicated  by  two  longitudinal  sections, 
(PL  II)  along  Mississippi  River,  one  (A-A)  on  the  Missouri  and 
the  other  (B-B)  on  the  Illinois  side,  and  by  three  east-west  sec- 
tions across  the  area  (PL  III). 

The  main  body  of  the  report  is  divided  into  three  parts,  the 
first  dealing  with  the  stratigraphy,  the  second  with  the  structure, 
and  a  third  with  the  oil  possibilities. 


MISSISSIPPI  VALLEY  AREA 


Table  1.  List  of  index  numbers  given  on  Plate  I,  including  names  of 
formations  and  elevations  of  the  tops  of  the  formations  where  contacts  are 
exposed. 

Illinois 


Map 
number 

Formation 

Elevation 
on  top  of 
formation 

Map 
number 

Formation 

Elevation 
on  top  of 
formation 

Adams 
County 
1 

Keokuk 

Ft.  above 
sea  level 

550 
580 
560 
550 
560 
555 
615 
615 
600 
600 
570 
570 

630 
640 
560 
560 
655 
660 
655 
640 

690 

b 

b 

625 
660 

600 
620 

625 
650 
680 
620 
430 
b 
680 

Adams 
County 
39 
40 
41 
42 
43 
44 
45 
46 
47 
48 
49 
50 
51 
52 
53 
54 
55 
Brown 
County 

1 
Calhoun 
County 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 
11 

11A 
12 
13 
14 
15 

Keokuk 

Ft.  above 
sea  level 

660 

2 
3 

Warsaw-Spergen . .  . 
Keokuk 

Warsaw-Spergen . .  . 
Warsaw-Spergen . .  . 
St.  Louis 

590 

585 

4 

Keokuk 

615 

5 

Keokuk 

a 
Keokuk 

6 

Keokuk 

Keokuk 

520 

7 

Warsaw-Spergen . .  . 
Hannibal 

600 

8 

Warsaw-Spergen..  . 
Warsaw-Spergen . .  . 
Warsaw-Spergen..  . 

Keokuk 

Keokuk 

b 

9 
10 
11 
12 

a 
Warsaw-Spergen . .  . 
Warsaw-Spergen . . 

a 

a 

a 

Keokuk 

Hannibal 

Hannibal 

a 

Silurian 

Hannibal 

595 
590 

13 

14 
15 
16 
17 

a 

Warsaw-Spergen . . . 
Warsaw-Spergen . . . 

Keokuk 

Keokuk 

b 

525 
485 

18 
19 
20 
21 
22 
23 
24 

Warsaw-Spergen . . . 
Warsaw-Spergen . . . 
Warsaw-Spergen . . . 
Warsaw-Spergen . . . 
a 

Keokuk 

Burlington 

Burlington 

Keokuk 

450 
600 

25 
26 

Silurian 

Hannibal ....... 

Silurian 

505 
520 

27 

Keokuk 

470 

28 

a 

Keokuk 

Silurian 

455 

29 

Silurian 

600 

30 
31 

Keokuk 

a 
Keokuk 

Hannibal 

Hannibal 

590 
520 

32 

a 
Silurian 

33 

Keokuk 

Keokuk 

Keokuk 

Hannibal 

455 

34 

Silurian 

b 

35 
36 

Maquoketa 

Hannibal 

Maquoketa 

Silurian 

490 
600 

37 
38 

Keokuk 

Keokuk 

b 
500 

INTRODUCTION 

Illinois — Continued 


Map 
number 


Calhoun 
County 
16 
17 
18 
19 
20 
21 
22 
22A 
23 
24 
25 
26 
27 
28 
29 
30 
31 
Hancock 
County 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 
11 
12 
13 
14 
15 
16 
17 
18 
19 
20 
21 
22 
23 
24 


Formation 


Maquoketa . 
Maquoketa. 
Silurian 
Kimmswick. 
Silurian 
Kimmswick . 
St.  Peter .  .  . 
Maquoketa . 

Silurian 

Silurian 
Burlington.  . 
St.  Louis.  .  . 
St.  Louis .  .  . 
St.  Louis .  .  . 
St.  Louis .  .  . 
St.  Louis .  .  . 
St.  Louis.  .  . 


Keokuk 

Keokuk 

Warsaw-Spergen . 
Warsaw-Spergen , 
Warsaw-Spergen , 

Keokuk 

Keokuk 

Keokuk 

Warsaw-Spergen . 
Warsaw-Spergen . 


a 
Warsaw- 
Warsaw- 
Warsaw- 
Warsaw- 
Keokuk 
Warsaw- 
Keokuk 
Warsaw- 
Keokuk 
Keokuk 
Warsaw- 
Warsaw 


■Spergen , 
Spergen . 
Spergen . 
Spergen . 


Spergen, 
Spergen. 


Spergen . 
Spergen , 


Elevation 
on  top  of 
formation 


Ft.  above 
sea  level 

560 
570 
490 
480 
565 
520 
540 

b 

460 
510 

b 

b 

b 

b 

b 

b 

b 


565 
560 
625 
620 
610 
580 
555 
570 
625 
615 


605 
605 
645 
640 
545 
595 
565 
580 
550 
535 
615 
590 


Map 
number 


Hancock 
County 

25 

26 

27 

28 

29 

30 

31 

32 

33 

34 

35 

36 

37 

38 

39 

40 

41 

42 

43 

44 

45 

46 

47 

48 

49 

50 

51 

52 

53 

54 

54A 

55 

56 

57 

58 

59 

60 

61 

62 

63 

64 

65 

66 


Formation 


-Spergen . 
■Spergen . 

-Spergen . 
-Spergen . 


Warsaw- 
Warsaw- 
Keokuk , 
Warsaw- 
Warsaw- 

Keokuk 

Warsaw-Spergen . 

Keokuk 

Keokuk 

Keokuk 

Keokuk 

Keokuk 

Keokuk 


a 

Keokuk 

Keokuk 

a 

a 

Keokuk 

Warsaw-Spergen . 

a 

a 

Keokuk 

Keokuk 

Warsaw-Spergen 

Keokuk 

Warsaw-Spergen 
Warsaw-Spergen 

a 
Keokuk 


a 

Keokuk 

Warsaw-Spergen 
Warsaw-Spergen 

Keokuk 

Warsaw-Spergen 
Warsaw-Spergen 

Keokuk 

Keokuk 


Warsaw-Spergen 
Warsaw-Spergen 


Elevation 
on  top  of 
formation 


Ft.  above 
sea  level 

580 
595 
530 
595 
605 
540 
600 
540 
540 
530 
565 
565 
620 


560 
550 


520 

585 


565 
560 
615 
585 
545 
580 

500 

540 

570 
580 
525 
570 

585 
535 
545 

600 
590 


10 


MISSISSIPPI  VALLEY  AREA 
Illinois — Continued 


Map 
number 


Hancock 
County 

67 
'68 
69 
70 
71 
72 
73 
74 
75 

J  ersey 
County 
1 

2 
3 
4 

5 
6 

7 

Pike 
County 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 
11 
12 
13 
14 
15 


Formation 


Warsaw- 
Warsaw- 
Warsaw- 
a 
a 
Warsaw- 
Keokuk 
Warsaw- 


Spergen . 
•Spergen . 
Spergen. 


Spergen 
Spergen 


Hannibal .  . 

a 

Silurian 

Maquoketa 
Silurian .  .  . 

a 
Hannibal .  . 


a 

Hannibal . 
Hannibal . 
Hannibal . 
Hannibal . 
Hannibal . 
Hannibal . 
Hannibal . 

a 
Burlington 
Hannibal . 
Hannibal . 

a 
Hannibal . 
Hannibal . 


Elevation 
on  top  of 
formation 


Ft.  above 
sea  level 

570 
580 

580 


580 
540 
565 


500 

500 
580 

520 

450 


590 
540 
520 

585 
555 
620 
550 

b 

575 
655 

765 
605 


Map 
number 


Pike 
County 
16 
17 
18 
19 
20 
21 
22 
23 
24 
25 
26 
27 
28 
29 
30 
31 
32 
33 
34 
35 
36 
37 
38 
39 
40 
41 
42 
43 
44 
45 
46 
47 
48 
49 
50 
51 
52 
53 


Formation 


Hannibal .  . 

a 

a 
Hannibal .  . 
Hannibal .  . 

a 
Hannibal .  . 
Hannibal .  . 
Hannibal .  . 
Burlington. 
Burlington. 
Hannibal .  . 
Hannibal.  . 
Hannibal .  . 

a 

a 
Hannibal .  . 
Hannibal .  . 
Silurian .  .  . 
Silurian .  .  . 
Hannibal .  . 
Hannibal .  . 
Hannibal .  . 
Hannibal .  . 
Hannibal . 
Hannibal .  . 
Hannibal .  . 
Hannibal .  . 
Hannibal .  . 
Hannibal .  . 
Hannibal .  . 
Hannibal .  . 
Hannibal .  . 
Maquoketa 
Hannibal .  . 
Silurian .  .  . 
Silurian. . . . 
Silurian 


Elevation 
on  top  of 
formation 


Ft.  above 
sea  level 

615 


700 
620 

575 
585 
580 

b 

b 

460 
600 
575 


600 
615 
495 
500 
620 
580 
590 
550 
550 
510 
460 
475 
475 
520 
545 
570 
595 
505 
600 
545 
505 
480 


INTRODUCTION 

Missouri 


11 


Map 
number 


Clark 
County 

1 

2 

3 

4 

5 

6 

7 

7a 

8 

9 

10 
11 
12 
13 
14 
15 

Lewis 
County 

1 

2 

3 

4 

5 

6 

7 

8 

9 
10 
11 
12 
13 
14 
15 
16 
17 
18 
19 
20 
21 
22 
23 


Formation 


Spergen 
Spergen 
Spergen 
Spergen 


Spergen 
Spergen 
Spergen 
Spergen 
Spergen 


Spergen 


Keokuk 
Warsaw- 
Warsaw- 
Warsaw- 
Warsaw- 
Keokuk 
Warsaw- 
Warsaw- 
Warsaw- 
Warsaw- 
Warsaw- 
Keokuk 

a 
Warsaw- 
Keokuk 

a 


Keokuk 

Warsaw-Spergen 

St.  Louis 

St.  Louis 

St.  Louis 

St.  Louis 

St.  Louis 

Warsaw-Spergen 
Warsaw-Spergen 

a 
Warsaw-Spergen 
Hannibal 

a 

Keokuk 

Keokuk 

Keokuk 

Keokuk 

a 

Keokuk 

Keokuk 

Keokuk 

Keokuk. ...... 

Keokuk ....... 


Elevation 
on  top  of 
formation 


Ft.  above 
sea  level 

550 
595 
575 
560 
580 
520 
600 
b 

605 
580 
600 
520 

590 
535 


580 
600 

b 

b 

b 

b 

b 

590 
580 

590 
b 

530 

535 

555 

b 

585 

530 

b 

570 
580 


Lincoln 
County 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 
11 
12 
13 
14 
15 
16 
17 
18 
19 
20 
21 
22 
23 
24 
25 
27 
28 
29 
30 
31 
32 
33 
34 
35 
36 
37 
38 
39 
40 
41 
42 
43 


Formation 


Plattin 

Plattin 

Kimmswick. 

Plattin 

St.  Peter.  .  . 
Joachim .  '. .  . 
St.  Peter .  .  . 

Plattin 

Plattin 

Plattin 

Maquoketa . 
Kimmswick. 
Kimmswick. 
Kimmswick . 
Kimmswick. 
Kimmswick. 

Plattin 

Kimmswick. 
Maquoketa . 
Hannibal .  .  . 
Maquoketa . 
Maquoketa. . 
Burlington.  . 
Burlington.  . 
Burlington.  . 
Burlington.  . 
Burlington.  . 

Plattin 

Plattin 

Plattin 

St.  Peter .  .  . 

Plattin  

a 

Plattin 

Plattin  

Burlington.  . 
Joachim 
Kimmswick . 
Burlington.  . 
Burlington.  . 
Maquoketa  . 
St.  Peter.  .  . 


Elevation 
on  top  of 
formation 


Ft.  above 
sea  level 

580 
610 

b 
700 

b 
650 

b 

720 
780 
720 
620 
520 
480 
500 
540 
540 
515 
600 
690 
740 
610 
530 

b 

b 

b 

b 

b 

b 

600 
690 
700 
610 

630 
730 

b 

580 
630 

1) 

1) 
640 
660 


12 


MISSISSIPPI  VALLEY  AREA 
Missouri — Continued 


Map 
number 


Lincoln 
County 

44 
45 
46 
47 
48 
49 
50 
51 
52 
53 
54 
55 
56 
57 
58 
59 
60 
60A 

61 
62 
63 
64 
65 
66 
67 
68 
69 
70 
71 
Marion 
County 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 
11 


Formation 


Kimmswick 

Plattin 

Devonian 

Kimmswick 

Devonian 

Plattin 

Kimmswick 

Burlington 

Burlington 

Burlington 

a 

Kimmswick 

Plattin 

Joachim 

St.  Peter 

St.  Peter 

Plattin 

St.  Peter  (Cap-au 

Gres  fault) 

St.  Louis 

St.  Louis 

WarsawT-Spergen . 

vSt.  Louis 

Warsaw-Spergen . 

Burlington 

St.  Louis 

Warsawr-Spergen . 
St.  Louis 

a 
St.  Louis 

Keokuk 

Burlington 

Burlington 

Burlington 

a 

a 

Burlington 

Burlington 

Burlington 

Burlington 

Hannibal 


Elevation 
on  top  of 
formation 


Ft.  above 
sea  level 

780 
740 
780 
620 
720 
510 
640 

b 

b 

b 

650 

b 

b 

b 

670 
680 

b 
b 
b 
b 
b 
b 
b 
b 

510 
b 


555 
b 
b 
b 


b 
b 
b 
b 
640 


Map 
number 


Marion 
County 
12 
13 
14 
15 
16 
17 
18 
19 
20 
22 
23 
24 
25 
26 
27 
28 
29 
30 
31 
32 
33 
34 
35 
36 
37 
38 
Pike 
County 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 
11 
12 
13 
14 
15 


Formation 


Hannibal.  . 
Hannibal .  . 
Hannibal .  . 

a 

a 
Hannibal .  . 
Hannibal .  . 
Hannibal .  . 
Burlington. 
Hannibal .  . 
Hannibal .  . 
Devonian.  . 
Louisiana. . 
Louisiana.  . 
Hannibal .  . 
Louisiana. . 

a 
Louisiana.  . 
Hannibal .  . 
Hannibal .  . 
Hannibal.  . 
Hannibal .  . 

a 

a 
Hannibal .  . 
Louisiana..  . 

a 
Maquoketa . 
Kimmswick 
Devonian . . 
Louisiana. . 
Hannibal .  . 
Maquoketa . 
Maquoketa . 
Hannibal.  . 
Maquoketa . 
Maquoketa , 
Kimmswick 
Hannibal .  . 
Louisiana. . 
Kimmswick 


Elevation 
on  top  of 
formation 


Ft.  above 
sea  level 

640 
560 
515 


500 
530 

b 

b 

665 
680 

b 

640 
570 
670 
660 

b 
b 
b 
b 
b 


590 
b 


490 
530 
610 
550 
670 
680 
550 
670 
560 
590 
565 
6S0 
560 
630 


INTRODUCTION 
Missouri — Continued 


13 


Map 
number 


Formation 


Pike 
County 
16 
17 
18 
19 
20 
21 
22 
23 
24 
25 
26 
27 
28 
29 
30 
31 
32 
33 
34 
35 
36 
37 
38 
39 
40 
41 
Ralls 
County 

1 

2 

3 

4 

5 

6 

7 

8 

9 
10 
11 
12 


Maquoketa 
Hannibal.  . 

a 
Hannibal .  . 
Kimmswick 
Maquoketa , 
Maquoketa . 
Kimmswick 
Maquoketa . 
Maquoketa . 

a 
Maquoketa . 

a 
Maquoketa . 
Maquoketa . 
Kimmswick 

Plattin 

Maquoketa . 
Maquoketa . 
Hannibal .  . 
Kimmswick 

Plattin 

Kimmswick 
Maquoketa . 
Maquoketa. 
Maquoketa . 

Louisiana. . 
Hannibal .  . 
Hannibal .  . 
Hannibal .  . 
Maquoketa . 
Maquoketa . 
Maquoketa . 
Hannibal .  . 
Hannibal .  . 
Hannibal .  . 
Kimmswick 
Kimmswick 


Elevation 
on  top  of 
formation 


Ft.  above 
sea  level 

720 
720 

685 
490 
570 
590 
560 
640 
670 

550 

540 
540 
650 
690 

b 

b 

700 
670 
'  690 
690 
770 
550 
540 


680 
710 
620 
640 
580 
560 
550 
630 
680 
675 
570 
590 


Map 
number 


Ralls 
County 
13 
14 
15 
16 
17 
18 
19 
20 
21 
22 
23 
24 
25 
26 
27 
28 
29 
30 
31 
32 
33 
34 
35 
36 
37 
38 
39 
40 
41 
42 
43 
44 
45 
46 
47 
48 
49 
50 
51 
52 


Formation 


Kimmswick 

a 

Plattin 

Hannibal .  . 
Kimmswick 
Devonian . . 
Hannibal .  . 
Hannibal .  . 
Hannibal .  . 
Hannibal.  . 
Hannibal .  . 
Hannibal .  . 
Burlington. 
Hannibal .  . 
Hannibal .  . 

a 
Burlington. 
Hannibal .  . 
Louisiana. . 
Kimmswick 

Plattin 

Hannibal.  . 
Maquoketa 
Kimmswick 
Plattin 

a 
Kimmswick 
Hannibal .  . 
Hannibal.  . 
Burlington. 
Burlington. 
Burlington. 
Hannibal .  . 
Hannibal.  . 
Burlington. 
Burlington. 
Burlington. 
Burlington. 
Burlington. 


Elevation 
on  top  of 
formation 


Ft.  above 
sea  level 

610 

580 
580 
580 
640 
680 
650 
590 
615 
605 
610 
b 

585 
585 

b 

620 
620 
635 
490 
670 
560 
580 
550 

500 
610 
640 

b 

b 

b 

600 
650 

b 

b 

b 

b 

b 


14 


MISSISSIPPI  VALLEY  AREA 
Missouri — Continued 


Map 

number 


St. 

Charles 
County 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 


Formation 


Warsaw-Spergen 
Warsaw-Spergen 

Keokuk 

Keokuk. ...... 

Keokuk 

Keokuk 

a 

Keokuk 

Keokuk 

Warsaw-Spergen 


Elevation 
on  top  of 
formation 


Ft.  above 
sea  level 


470 
b 
b 
b 
b 
b 


b 

b 

510 


Map 
number 


St. 

Charles 
County 

11 

12 

13 

14 

15 

16 

17 

18 

19 


Elevation 

Formation 

on  top  of 

formation 

Ft.  above 

sea  level 

St.  Louis 

b 

St.  Louis 

b 

a 

Warsaw-Spergen . .  . 

520 

Keokuk 

490 

Keokuk 

460 

a 

Hannibal 

470 

Kimmswick 

460 

a  Well  known  to  reach  "Trenton." 
frLevel  data  not  available. 


CHAPTER  II— STRATIGRAPHY 
General  Statement 

The  succession  of  the  stratified  rocks  which  occur  at  the 
surface  in  this  area  includes  formations  ranging  in  age  from  Jef- 
ferson City  of  the  Ordovician  system  to  Carbondale  of  the  Penn- 
sylvanian.  Rocks  older  than  those  that  outcrop  are  known  from 
drill  records  and  may  be  seen  in  outcrop  on  the  flanks  of  the 
Ozarks  to  the  southwest  and  in  northern  and  central  Wisconsin 
to  the  north,  but  inasmuch  as  these  rocks  are  not  known  to  con- 
tain petroleum  and  were  not  studied,  they  will  not  be  discussed 
here.  Plate  IV  shows  a  generalized  section  of  the  rocks  exposed 
within  the  area  in  the  northern  and  southern  portions. 

Situated  as  this  region  is  on  the  flanks  of  the  old  Paleozoic 
highlands  of  the  Ozark  region,  the  formations  deposited  during 
that  time  reflect  to  a  greater  degree  the  oscillations  and  shift- 
ings  of  the  sea  than  do  the  strata  lain  down  farther  east  toward 
the  center  of  the  Illinois  basin.  During  periods  of  emergence, 
the  associated  slight  warpings  gave  rise  to  local  high  and  low 
areas  so  that  during  the  periods  of  erosion,  formations  have  been 
entirely  eroded  from  the  higher  areas,  but  remained  undisturbed 
in  the  low  spots  giving  rise  to  unequal  and  irregular  distribution. 
Furthermore,  the  extent  to  which  the  seas  transgressed  upon 
these  highlands  varied  with  different  periods  or  even  epochs. 
Some  formations  are  thus  seen  to  rest  upon  progressively  older 
strata  towards  the  Ozarks.  Also,  the  variation  in  proximity 
of  the  shore  line  at  different  places  made  its  influence  felt  on  the 
character  of  the  sediments  so  that  the  same  formation  may  vary 
greatly  in  lithologic  character  in  different  localities.  Some 
deposits  lain  down  in  bays  from  the  main  seas  are  found  at  the 
same  elevations  with  older  formations  on  both  sides. 

The  near-shore  characteristics  mentioned  are  especially 
pronounced  for  the  Silurian,  Devonian  and  early  Lower  Missis- 
sippian,  but  the  area  in  which  these  formations  come  to  the  sur- 
face is  limited  to  southern  Calhoun  and  southwestern  Jersey 
counties  in  Illinois  and  the  eastern  portions  of  Lincoln,  Pike  and 
Ralls  counties  in  Missouri.  Much  detailed  work  needs  to  be 
done  in  this  area  before  all  the  details  of  the  complicated  strati- 
graphic  relations  are  known.     Because  the  data  will  have  to  be 

(15) 


16  MISSISSIPPI  VALLEY  AREA 

obtained  from  drill  records  and  cuttings  over  much  of  this  area, 
samples  of  cuttings  from  all  deep  holes  should  be  carefully  col- 
lected and  logs  be  preserved. 

Ordovician  System 

Formations  of  the  Ordovician  system  outcrop  along  a  belt 
5  to  15  miles  wide,  extending  from  southwestern  Jersey  County 
westward  across  Calhoun  County,  Illinois,  and  thence  across 
Mississippi  Valley  to  eastern  Lincoln  County  in  Missouri.  The 
southern  limit  of  the  belt  of  outcrop  is  terminated  by  a  large  fault 
(Cap-au-Gres)  which  juxtaposes  rocks  of  Mississippian  age  with 
those  of  Ordovician  age.  In  Missouri,  the  Ordovician  rocks  out- 
crop along  a  northward  pitching  arch  which  crosses  eastern  Lin- 
coln, Pike  and  Ralls  counties,  but  disappear  beneath  younger 
formations  before  Marion  County  is  reached. 

The  formations  exposed  include  the  Jefferson  City  group, 
the  St.  Peter  group,  Joachim  formation,  Plattin  formation, 
Kimmswick  limestone,  Fernvale  limestone,  and  Maquoketa 
shale. 

JEFFERSON  CITY  GROUP 

The  term  "Jefferson  City  Group"  is  here  used  in  the  same 
sense  as  employed  by  Dake1  and  includes  both  Cotter  and  Powell 
formations  as  well  as  typical  Jefferson  City. 

Rocks  referable  to  this  group  outcrop  along  the  bluff  and  in 
the  ravines  cutting  the  bluff  in  Lincoln  County,  Missouri,  from  the 
Cap-au-Gres  fault  northward  to  within  half  a  mile  of  Foley,  a 
distance  of  about  2  miles.  Other  outcrops  of  this  group  were 
seen  near  the  bottom  of  a  large  ravine  north  of  the  road  near  the 
center  of  sec.  4,  T.  49  N.,  R.  2  E.,  and  are  reported  from  the 
south  side  of  Sandy  Creek  in  sec.  35,  T.  50  N.,  R.  2  E.,2  from  the 
Mississippi  River  bluff  north  of  the  Cap-au-Gres  fault  in  Cal- 
houn County,  Illinois.3 

Since  both  the  "Jefferson  City  Group"  and  the  overlying 
St.  Peter  group  are  below  any  known  oil-bearing  horizon  in  this 
region,  no  time  was  spent  in  detailed  study  of  these  formations. 


iDake,  C  L.,  The  problem  of  the  St.  Peter  sandstone;  Missouri  School  of  Mines  and 
Metallurgy.  Bulletin,  Vol.  VI.,  no.  1.  p.  12,  1921. 

'Potter.  W.  B.,  Geology  of  Lincoln  County  in  preliminary  report  on  iron  ores  and  coal 
fields:  Geological  Survey  of  Missouri,  1872. 

•Weller.  Stuart,  Geology  of  southern  Calhoun  County,  111.:  State  Geol.  Survey  Bull.  4, 
p.  221.  1907. 


STRATIGRAPHY  17 

As  observed,  the  strata  consist  essentially  of  gray  to  buff, 
earthy,  dolomitic  limestone  with  interbedded  sandy  and  cherty 
layers.  The  following  section  measured  in  the  bluff  about  1}4 
miles  south  of  Foley  will  serve  to  show  the  general  character  of 
the  formation: 

Thickness 

Description  of  strata  Feet  Inches 

Limestone,  dolomitic,  gray,  sandy 1  6 

Limestone,  white,  earthy,  in  uneven  beds 1  2 

Limestone,  gray,  earthy,  in  uneven  beds 2  6 

Limestone,  white,  earthy,  and  knotty  chert 1  6 

Limestone,  gray,  sandy 2  — 

Limestone,   dolomitic,   white,   earthy  and  laminated  gray, 

regular   beds   2   to   12  inches   alternating   with   sandy 

layers 16  — 

Sandstone,  gray,  slightly  calcareous 5  — 

Limestone,    dark,    porous,    sandy,    brecciated    and    cherty, 

uneven  top  surface 3  — 

Limestone,  blue-gray,  weathers  brown;  sandy  and  oolitic.  .  1  — 
Dolomite,   porous,   brown,   cherty  at  base    (contorted  and 

brecciated) 3  — 

Dolomite,    dark   blue    gray,    porous    and    finely    granular, 

earthy  at  base 10  — 

Concealed  to  fiat 50  — 

The  greatest  exposed  thickness  of  strata  belonging  to  this 
group  is  about  130  feet.  This  formation,  though  outcropping 
only  in  a  limited  area,  underlies  the  whole  region. 

ST.  PETER  GROUP 

Heretofore,  the  massive  sandstone  above  the  "Jefferson 
City  group"  has  in  this  area  been  considered  a  single  stratigraphic 
unit  and  has  been  referred  to  as  the  saccharoidal  or  St.  Peter 
sandstone.  Recent  work  to  the  south  in  Ste.  Genevieve  and 
Jefferson  counties,  Missouri,  however,  shows  the  St.  Peter  group 
to  consist  of  two  formations,  the  massive  St.  Peter  sandstone 
above,  and  dolomite  and  sandstone,  together  known  as  the 
Everton  formation,  below.  In  this  area  dolomitic  beds  have 
been  observed  in  the  middle  portion  of  the  St.  Peter  group  and  as 
the  thickness  of  the  St.  Peter  in  this  region  is  equal  to  the  com- 
bined thickness  of  the  St.  Peter  and  Everton  beds  farther  south, 
it  is  probable  that  both  formations  are  also  present  here. 

Though  outcropping  over  only  a  limited  extent,  the  St. 
Peter  group  underlies  the  entire  region;  is  a  noted  water  carrier, 
and  in  the  northern  part  of  the  region  provides  many  artesian 


18  MISSISSIPPI   VALLEY  AREA 

wells  of  fresh  water  which  farther  south  becomes  increasingly 
saline.  In  this  area  the  top  of  the  St.  Peter  group  is  considered 
the  base  of  any  probable  oil  production. 

The  best  exposures  of  this  group  are  found  in  Lincoln  County, 
Missouri,  and  Calhoun  County  in  Illinois,  and  at  least  one  ex- 
posure is  known  from  Ralls  County,  Missouri.4 

In  Lincoln  County,  the  St.  Peter  group  is  prominent  in  the 
river  bluffs  from  the  Cap-au-Gres  fault  to  about  a  mile  north  of 
Foley.  It  is  also  found  along  the  ravines  and  creeks  back  from 
the  bluff  for  a  distance  of  3  or  4  miles.  Other  outcrops  of  St. 
Peter  were  observed  along  Mill  Creek  and  its  tributaries  in  sees. 
28  and  33,  and  near  the  head  of  Sandy  Creek  in  sees.  4  and  9, 
T.  51  N.,  R.  1  W. 

In  Calhoun  County,  Illinois,  the  St.  Peter  group  outcrops 
in  the  Mississippi  bluff  between  West  Point  and  Dogtown  land- 
ings, where  it  stands  as  a  sheer  bluff  and  does  not  lend  itself  to 
detailed  study. 

Wherever  observed,  the  St.  Peter  is  a  massive  sandstone  in- 
distinctly bedded  or  stratified.  The  color  on  the  weathered 
surface  is  usually  brown,  but  in  protected  places  white  or  yellow. 
It  is  moderately  coarse  grained;  the  grains,  the  surfaces  of  which 
are  frosted,  are  loosely  cemented,  well  rounded,  and  of  uniform 
size.  Where  the  sandstone  outcrops  in  the  bed  of  streams  and 
is  subject  to  the  action  of  running  water  and  other  forces  of 
erosion,  the  bedding  is  more  distinct,  surfaces  often  ripple  marked, 
and  cross-bedding  shown.  At  two  localities  dolomite  was  found 
interbedded  with  the  sandstone.  At  the  east  point  of  the  bluff 
about  Yi  mile  south  of  Foley,  a  6-foot  bed  of  dolomite  was  ob- 
served, and  in  the  ravine  about  a  mile  south  of  the  last  locality, 
many  beds  of  dolomite  4  to  6  inches  thick  were  found  inter- 
layered  with  sandstone,  below  which  more  massive  sandstone, 
showing  ripple  marks  occurred. 

The  stratigraphic  relations  of  the  St.  Peter  group  to  the 
underlying  formations  were  not  observed.  The  contact  of  the 
St.  Peter  with  the  overlying  formation  which  was  noted  at 
several  places,  appears  to  be  conformable,  the  St.  Peter  group 
apparently  grading  into  the  overlying  Joachim  dolomite.  The 
thickness  of  the  St.  Peter  group  as  developed  in  this  area  is  be- 
tween 125  and  150  feet. 


*Shepard,  E.  M.,  Underground  waters  of  Missouri;  U.  S.  Geol.  Survey  Water  Supply- 
Paper  195,  p.  54,  1907. 


STRATIGRAPHY  19 


JOACHIM  DOLOMITE 

The  Joachim5  dolomite,  also  known  as  the  first  Magnesian 
limestone  of  the  older  writers  is  exposed  as  a  narrow  belt  bordering 
the  outcrops  of  St.  Peter  sandstone  and  is  best  exposed  in  Lincoln 
County,  Missouri,  and  Calhoun  County,  Illinois,  but  local  out- 
crops are  also  found  in  Ralls  County,  Missouri,  namely  near  the 
south  line  of  sec.  21,  T.  55  N.,  R.  4  W.,  and  near  the  town  of 
Spaulding,  sec.  25,  T.  56  N.,  R.  6  W.  Specific  locations  of  ob- 
served outcrops  in  Lincoln  County,  Missouri,  are  in  the  Missis- 
sippi River  bluff  about  Yi  mile  north  of  Foley;  along  Sandy 
Creek  in  the  southwest  corner  of  sec.  30  and  S.  }/£,  sec.  32,  T.  50 
N.,  R.  2  E.;  S.  y2,  sec.  7,  T.  50  N.,  R.  1  E.;  the  SE  J4,  sec.  10, 
T.  50  N.,  R.  1  W.,  and  near  the  head  waters  of  Sandy  Fork  in 
the  northwest  portion  of  T.  51  N.,  R.  1  W.  In  Calhoun  County, 
Illinois,  the  best  exposure  of  Joachim  is  found  at  the  abandoned 
quarry  in  the  river  bluff  near  West  Point  landing. 

As  seen  in  the  quarry  in  Calhoun  County,  the  Joachim  is  a 
massive  dolomite  occurring  in  beds  up  to  several  feet  thick.  The 
color  on  the  fresh  surface  is  gray  or  yellow,  but  on  the  weathered 
face  it  is  often  brown.  It  is  finely  granular  to  crystalline,  but 
some  beds  may  be  earthy  and  in  the  lower  portion  sandy.  The 
lithologic  characters  of  the  rock  are  surprisingly  uniform  through- 
out its  belt  of  outcrop,  and  it  can  easily  be  recognized  by  its 
yellowish  color  and  finely  granular  to  crystalline  texture.  Fos- 
sils are  scarce,  and  wanting  in  most  exposures. 

In  Calhoun  County,  Illinois,  the  formation  is  approximately 
75  feet  thick,  but  in  Lincoln  County,  Missouri,  it  is  not  much 
over  50  feet.  The  relation  of  the  Joachim  with  the  underlying 
St.  Peter  has  already  been  discussed,  and  its  relation  to  the  over- 
lying Plattin  appears  to  be  unconformable.  In  Calhoun  County 
the  contact  is  more  or  less  indistinct,  and  the  formation  appears 
to  grade  into  the  overlying  Plattin  limestone  without  any  dis- 
tinct break.  The  upper  beds  of  the  Joachim,  however,  are  some- 
what more  argillaceous  than  the  others.  Westward  in  Lincoln 
County,  Missouri,  the  Joachim  is  separated  from  the  Plattin 
by  a  distinct  shale  several  feet  in  thickness.  The  shale  is  not 
well  developed  in  the  bluff,  but  becomes  increasingly  prominent 
westward  and  reaches  a  thickness  of  about  four  feet  in  western 


5Winslow,  Arthur,  Lead  and  zinc  deposits  of    Missouri:     Mo.   Geol.   Survey,   Vol.   VI, 
1st  ser.,  p.  352,  1894. 


20  MISSISSIPPI  VALLEY  AREA 

Lincoln  County.  It  is  green  in  color  and  in  some  places  contains 
nodules  of  earthy  limestone.  A  similar  shale,  also  present  at  this 
horizon  in  Ralls  County,  Missouri,  may  be  seen  at  the  localities 
mentioned  as  having  outcrops  of  the  Joachim.  At  the  outcrop 
near  Spaulding  in  Ralls  County  the  shale  is  distinctly  sandy. 

PLATTIN  LIMESTONE 

The  Plattin6  limestone  overlying  the  Joachim,  outcrops  in 
the  same  general  vicinity  as  that  formation,  but  because  of  its 
greater  thickness,  it  is  exposed  in  a  broader  belt.  In  Lincoln 
County,  Missouri,  it  outcrops  for  several  miles  from  both  sides 
of  a  line  drawn  from  the  river  bluff  half  way  between  Apex  and 
Foley  northwestward  to  a  point  about  4  miles  northeast  of  Louis- 
ville. Its  outcrop  in  Pike  County,  Missouri,  is  limited  to  a 
small  area  near  the  south  line  of  the  county  southwest  of  Edge- 
wood.  In  Ralls  County,  it  outcrops  at  localities  mentioned  as 
having  outcrops  of  Joachim.  On  the  Illinois  side  of  Mississippi 
River,  it  is  exposed  only  in  the  river  bluffs  near  West  Point  Land- 
ing in  Calhoun  County. 

Though  somewhat  variable  in  lithologic  character,  it  is 
readily  distinguishable  from  either  the  overlying  or  underlying 
formation.  On  the  weathered  surface  the  color  is  generally  gray, 
but  when  freshly  broken  it  is  drab  or  bluish.  It  is  massive  with 
bedding  often  indistinct.  The  weathered  surface  is  carious 
in  many  places,  the  pits  varying  in  diameter  from  a  fraction  of  an 
inch  to  more  than  a  foot.  The  texture  varies  from  granular  to 
lithographic.  Coarsely  granular,  fossiliferous  beds  are  prom- 
inent in  the  lower  50  feet  and  in  the  upper  portion.  Dense, 
lithographic  beds  characterized  by  conchoidal  fracture  occur  at 
different  horizons  throughout  the  formation,  but  are  most  abund- 
ant near  the  top  and  bottom.  The  larger  part  of  the  formation 
especially  the  central  portion,  consists  of  finely  granular,  dolo- 
mitic  limestone,  drab  in  color,  but  on  closer  examination  an 
intimate  mixture  of  earthy  yellowish  dolomite  with  the  drab  can 
be  observed.  The  upper  10-15  feet  of  the  Plattin  wherever  ex- 
posed, consists  of  layers  6  inches  to  2  feet  thick  of  dense,  drab  to 
blue,  lithographic  limestone,  separated  by  partings  Y±  to  2  inches 
thick  of  drab,  calcareous  shale  which  is  petroliferous,  thin  slivers 
of   which   burn   when   lighted   with    a   match.     The   limestone 


•Buckley,  E.  R.,  and  Buehler,  H.  A.,  The  quarrying  industry  of  Missouri:     Missouri 
Bureau  of  Geology  and  Mines,  Vol.  II,  2nd.  ser.,  p.  Ill,  1904. 


STRATIGRAPHY  21 

weathers  white,  and  where  it  occurs  in  a  bluff,  it  resembles 
strongly  a  wall  of  masonry.  Where  this  horizon  makes  up  the. 
surface  rock,  it  weathers  to  a  light,  spongy,  porous  mass  so  soft 
it  can  be  scratched  with  the  finger-nail,  and  preserves  beautifully 
the  enclosed  fossil  forms.  It  is  for  this  horizon  that  Rowley  pro- 
posed the  name  Auburn  Chert.7 

The  thickness  of  the  Plattin  is  not  much  less  than  200  feet 
in  Lincoln  County,  Missouri,  for  180  feet  may  be  seen  in  the 
bluff  about  1H  miles  north  of  Foley.  In  Calhoun  County, 
Illinois,  it  does  not  appear  to  be  greater  than  125  feet,  and  judging 
from  well  records,  it  probably  thins  out  to  the  north.  There  is  a 
suggestion  also  that  where  the  Plattin  is  thickest  the  Joachim 
is  thinnest  and  vice  versa. 

KIMMSWICK  ("TRENTON")  LIMESTONE 

The  Kimmswick8  limestone  which  overlies  the  Plattin 
is  best  exposed  in  northeastern  Lincoln  County,  a  strip  running 
northwest-southeast  across  central  Pike  County  and  in  the  gen- 
eral vicinity  of  New  London  in  Ralls  County,  Missouri.  In 
Illinois,  the  best  exposures  may  be  seen  in  the  Mississippi  River 
bluff  in  the  vicinity  of  Batchtown  and  along  the  Illinois  River 
bluff  in  southwestern  Jersey  County. 

Lithologically,  the  Kimmswick  is  essentially  a  gray,  some- 
times tinted  blue  or  pink,  coarsely  granular  limestone.  Locally, 
however,  especially  in  the  upper  portion  there  is  found  consider- 
able variation.  Where  the  Cap-au-Gres  fault  intersects  the 
bluff  in  Lincoln  County,  the  upper  6  feet  of  the  Kimmswick  con-' 
sists  of  dense,  massive,  hard,  finely  granular  limestone,  some- 
what porous,  which  on  weathering  shows  a  knotty  character 
and  is  mottled  pink  and  gray.  Similar  limestone  of  like  thick- 
ness is  found  capping  the  Kimmswick  along  Missouri  River 
about  \y<i  miles  west  of  Hamburg  in  St.  Charles  County,  Mis- 
souri. Over  most  of  Pike  and  Ralls  counties  in  Missouri,  the 
upper  portion  of  the  Kimmswick  is  light  gray,  fine-grained  lime- 
stone which  weathers  into  thin  layers.  This  character  also  pre- 
vails in  southwestern  Jersey  County,  Illinois,  but  in  Calhoun 
and  Lincoln  counties,  the  fine-grained,  gray  beds  of  the  upper 
Kimmswick  are  not  so  much  in  evidence.     This  phase  seems  best 


'Rowley,  R.  R.,  Geology  of  Pike  County:  Missouri  Bur.  of  Geology  and  Mines,  Vol. 
VIII,  2nd.  ser.,  1907. 

"Buckley,  E.  R.,  and  Buehler,  H.  A.,  The  quarrying  industry  of  Missouri:  Missouri  Bur. 
of  Geology  and  Mines,  Vol.  II,  2nd.  ser.,  p.  Ill,  1904. 


22  MISSISSIPPI  VALLEY  AREA 

developed  in  the  northern  and  eastern  portion  of  the  area.  These 
fine-grained  layers  are  not  a  distinct  unit,  but  grade  downward 
into  the  granular  rock  and  are  inter-bedded  with  it.  The 
typical  index  fossil  Receptaculites  is  most  abundant  in  this  upper 
phase  of  the  Kimmswick. 

The  Kimmswick  is  massive,  and  where  it  outcrops  along 
the  streams,  forms  cliffs,  shows  only  traces  of  bedding,  and  the 
weathered  face  is  characterized  by  the  peculiar  pitting  which  is 
so  prominent  in  most  of  the  Plattin.  Chert,  though  not  abun- 
dant, is  scattered  throughout  the  formation. 

The  greatest  observed  thickness  was  about  120  feet,  which  is 
present  in  the  river  bluff  in  Lincoln  County,  Missouri,  near  Apex. 
In  Calhoun  County,  Illinois,  there  does  not  appear  to  be  much 
over  60  feet,  but  the  average  thickness  of  the  formation  is  prob- 
ably not  much  less  than  100  feet. 

The  break  between  the  Kimmswick  and  Plattin  is  in  most 
cases  distinct,  and  the  change  from  the  dense  lithographic  lime- 
stones of  the  Plattin  to  the  granular  limestone  of  the  Kimmswick 
is  accomplished  within  2  feet  or  less.  On  the  other  hand,  the 
presence  throughout  the  region  of  outcrop,  of  the  thin,  litho- 
graphic phase  at  the  top  of  the  Plattin,  precludes  any  erosional 
surface  separating  the  two  in  this  area  and  the  two  formations 
appear  conformable. 

MAQUOKETA  SHALE 

The  Maquoketa  shale  is  well  exposed  in  northeastern  Lin- 
coln County,  eastern  Pike  County,  and  central  and  southeastern 
Ralls  County  in  Missouri;  in  both  the  Illinois  River  and  Missis- 
sippi River  bluffs  in  central  Calhoun  County,  and  in  the  Illinois 
River  bluffs  in  southwestern  Jersey  County  in  Illinois. 

Unlike  the  previously  described  formations,  the  Maquoketa 
does  not  underlie  the  whole  region.  It  is  present  throughout  the 
Illinois  portion  of  the  area,  and  outcrops  in  Lincoln  and  Pike 
counties,  Missouri,  but  in  north  central  Ralls  County,  Devonian 
limestone  is  seen  resting  directly  on  Kimmswick  limestone,  and 
drill  records  from  Scotland,  Knox,  Monroe,  Montgomery,  War- 
ren and  St.  Charles  counties,  Missouri,  show  no  shale  body 
comparable  to  the  Maquoketa  to  be  present.  Field  relations 
in  Ralls  County  probably  best  observed  along  the  ravines  in  the 
east  central  portion  of  sec.  29,  T.  56  N.,  R.  4  W.,  south  central 
portion  of  sec.  24,  T.  56  N.,  R.  5  W.,  and  in  the  vicinity  of  Shiel 


STRATIGRAPHY  23 

in  the  eastern  part  of  sec.  20,  T.  56  N.,  R.  6  W.,  show  that  the 
Maquoketa  was  eroded  in  early  Devonian  times,  and  that  with 
the  advance  of  the  middle  or  late  Devonian  sea  from  the  north, 
deposits  of  sandstone  and  limestone  were  lain  down  in  this  eroded 
area  and  are  now  found  at  the  same  elevation  as  the  older  rocks 
which  formed  the  shore  line.  Data  showing  the  exact  location 
of  this  bay  are  not  available,  but  it  extended  southward  at  least 
as  far  as  Ralls  County. 

The  Maquoketa  is  essentially  a  calcareous  shale  of  greenish- 
gray  color,  which  on  weathering  becomes  olive  green.  The 
amount  of  calcareous  material  varies  but  increases  north  and 
west  so  that  in  Pike  and  Ralls  counties,  Missouri,  the  shale  is 
predominantly  flaggy  consisting  of  harder,  non-laminated,  earthy 
limestone  layers  one  inch  to  one  foot  thick  separated  by  less 
calcareous  shale  of  approximately  equal  thickness.  Farther 
south  in  Calhoun  and  Jersey  counties,  the  upper  portion  is  more 
argillaceous  and  siliceous,  and  the  flaggy  character  is  evident  only 
in  the  lower  portion.  Locally,  in  western  exposures,  as  ob- 
served near  the  center  of  sec.  13,  T.  54  N.,  R.  5  W.,  the  upper 
3  feet  of  Maquoketa  consist  of  coarsely  granular,  reddish  lime- 
stone which  is  abundantly  fossiliferous.  The  apparent  increase 
in  lime  content  to  the  north  and  west  suggests  that  the  Ma- 
quoketa once  extended  much  farther  westward  than  now  found. 

In  Pike  County,  Missouri,  there  is  seen  above  the  flaggy, 
green  Maquoketa  30  feet  or  more  of  thinly  laminated,  black  shale, 
which  weathers  blue-gray,  but  is  black  in  the  fresh  surface. 
This  shale  is  characterized  by  the  presence  of  abundant  lingulas, 
and  is  separated  from  the  flaggy  shale  of  the  Maquoketa  by  an 
unconformity  marked  by  a  thin,  sandy  layer  containing  much 
pyrite  and  highly  polished,  phosphatic  nodules.  This  shale 
answers  the  description  of  the  Hamilton  shale  of  Rowley,9  but 
since  in  sec.  19,  T.  54  N.,  R.  2  W.,  along  the  south  bank  of  Grassy 
Creek,  it  occupies  a  position  below  the  Noix  oolite  of  the  Silurian 
and  above  the  flaggy  Maquoketa,  it  must  be  early  Silurian  or 
late  Maquoketa. 

In  the  bluff  farther  west  where  the  Silurian  limestone  is  ab- 
sent, the  Sweetland  Creek  shale  rests  on  the  black  shale  of  the 
Maquoketa.  The  thickness  of  the  formation  varies  from  about 
60  feet  in  the  southernmost  exposures  of  Missouri  in  Lincoln 
County,  to  about  100  to  125  feet  in  Pike  and  Ralls  counties.   ,  II 


9Rowley,  R.  R.,  Geology  of  Pike  County:     Missouri  Bur.  of  C.  oology  and  Mines,  Vol. 
VIII,  2nd  ser.,  p.  24,  1907. 


24  MISSISSIPPI  VALLEY  AREA 

also  increases  in  thickness  to  the  east  as  drill  records  in  eastern 
Adams  County,  Illinois,  show  thicknesses  of  150-200  feet  of  shale. 
Because  of  the  more  resistant  character  of  the  shale,  the 
contact  of  the  Maquoketa  with  the  underlying  formation  is 
not  commonly  exposed,  but  in  Calhoun  County,  Illinois,  where 
the  contact  has  been  observed,  Weller10  reports  6  inches  of  red, 
residuary  clay  with  embedded  chert  fragments  beneath  the  shale 
and  considers  this  evidence  for  a  long  erosion  period  separating 
the  two  epochs  of  deposition. 

Silurian  System 

The  Silurian  outcrops  over  only  a  limited  area  along  the 
flanks  of  the  uplift  which  crosses  Ralls,  Pike,  and  Lincoln  coun- 
ties, Missouri,  and  Calhoun  and  southwestern  Jersey  counties  in 
Illinois  (PL  V,  A). 

ALEXANDRIAN  SERIES 

Only  the  lower  Silurian  formations  known  as  the  Alexan- 
drian11 series  are  present.  This  series  includes  the  Sexton  Creek 
limestone  which  is  considered  of  Brassfield  age  and  the  Edgewood 
formation. 

Field  studies  show  that  the  Silurian  does  not  extend  as  far 
south  as  the  Cap-au-Gres  fault  in  Lincoln  County,  and  does  not 
continue  much  farther  north  than  Louisiana  in  Pike  County, 
Missouri.  Westward,  Silurian  rocks  were  observed  to  within 
2  J/2  miles  southwest  of  New  London  in  Ralls  County.  West  of 
here,  exposures  show  that  Silurian  rocks  were  eroded  probably 
during  early  Devonian  times  and  drill  records  of  surrounding 
regions  in  Missouri  show  no  Silurian,  so  that  in  Missouri  the 
Silurian  rocks  appear  to  occupy  a  tongue-like  extension  or  bay 
extending  westward  from  the  Illinois  basin.  In  Illinois,  Silurian 
rock  underlies  practically  the  whole  region  except  an  area  be- 
tween Quincy  and  Warsaw  along  Mississippi  River. 

EDGEWOOD    FOKMATION 

The  Edgewood  formation  is  divided  into  two  members: 
the  Bowling  Green  dolomite  above,  and  the  Cyrene  dolomite 


1#Weller,  Stuart,  Geology  of  southern  Calhoun  County:  111.  State  Geol.  Survey  Bull.  4, 
p.  223,  1907. 

"Savage,  T.  E.,  Stratigraphy  and  paleontology  of  the  Alexandrian  series  in  Illinois  and 
Missouri:     111.  State  Geol.  Survey  Bull.  23,  p.  68,  1917. 


Illinois  State  Geological  Survey. 


Bulletin  No.  45,  Plate  V. 


Steeply  dipping  Silurian  limestone  along  the  Cap-au-gres  fault, 
Jersey  County,  Illinois. 


miles  west  of  Grafton, 


^ap»> 


Ledge  of  Noix  oolite  above  Maquoketa  shale  in  bed  of  creek  on  east  side  of  road  about 
5  miles  south  of  Hamburg,  Calhoun  County,  Illinois. 


Illinois  State  Geological  Survey. 
Feet 


200  yards  downstream 


ran 


o   l   o 


J-QJ 


o    I    o 


ran 


o   I  o 


Dolomite,  massive,  brown. 
(Bowling  Green  dolomite) 


Limestone,  granular,  in 
beds  2-6  inches. 
Separated  by  shale 
partings  1/4  to  1   inch 
thick.  (Cyrene  limestone) 


Oolite,  granular, 
fossiliferous. 
(Noix  oolite) 


Limestone,  bluish, 
earthy,  magnesian 
(abundant  Edgewood 
corals) 


Shale,  blue-grey 
(Maquoketa) 


Bulletin  Xo.  45,  Plate  VI. 


400  yards  downstream 


Dolomite,  massive,  brown. 
(Bowling  Green  dolomite) 


Limestone,  massive, 
coarsely  granular 
and  crystalline. 


Cyrene 


limestone 


- —  I  -     Limestone,  thin,  shaly. 


'EIErEE:     Shale,  blue-grey. 
=-=      (Maquoketa) 


Sections  taken  at  intervals  along  Grassy  Creek,  Sec.  24,  T.  54  N.,  R.  3  W.,   Pike  County,  Missouri. 


STRATIGRAPHY  25 

and  limestone  below.  A  portion  of  the  Gyrene  member  which 
is  oolitic  is  called  the  Noix  oolite.  Savage12  considers  the  oolite 
equivalent  to  the  upper  portion  of  the  Cyrene. 

The  upper  portion  of  the  Edgewood  (Bowling  Green  mem- 
ber) is  a  lithologic  unit  throughout  the  area,  but  the  lower  por- 
tion shows  considerable  variation.  At  most  exposures,  the  Noix 
oolite  constitutes  the  basal  Silurian  formation,  and  rests  directly 
on  Maquoketa  shale  (PL  V,  B),  although  in  Grassy  Creek  in 
sec.  24,  T.  54  N.,  R.  3  W.,  the  Noix  oolite  is  separated  from  the 
Maquoketa  by  from  1  to  3  feet  of  earthy,  magnesian  limestone 
which  is  abundantly  fossiliferous.  In  general,  it  may  be  said 
that  the  Noix  oolite  forms  the  basal  formation  of  the  Silurian 
in  the  vicinity  of  the  river  bluffs  on  both  Illinois  and  Missouri 
sides.  Locally,  however,  as  in  southern  Calhoun  County  and 
along  Grassy  Creek  in  sec.  24,  T.  54  N.,  R.  3  W.,  of  Pike  County, 
Missouri,  the  basal  Silurian  formation  is  a  coarsely  crystalline, 
gray  fossiliferous  limestone.  Eastward  in  Jersey  County,  Il- 
linois, no  Noix  oolite  was  seen,  and  westward  in  Missouri  near 
Bowling  Green  and  Cyrene  in  Pike  County  and  northwestern 
Lincoln  County,  the  basal  Silurian  is  a  fossiliferous,  earthy,  mag- 
nesian limestone  up  to  20  feet  thick  and  no  Noix  oolite  appears 
to  be  present.  In  the  southeast  corner  sec.  13,  T.  53  N.,  R.  3 
W.,  near  Bowling  Green,  about  3  feet  of  earthy,  magnesian  lime- 
stone with  abundant  oolites  typical  of  the  Noix  occur  below  the 
fossiliferous  Cyrene.  Unfortunately  no  fossils  are  associated 
with  this  oolite,  but  the  relations  shown  suggest  that  the  Noix 
is  stratigraphically  below  beds  referred  to  Cyrene.  It  is  not 
improbable  that  detailed  stratigraphic  work  in  this  region  will 
show  that  both  the  Noix  oolite  and  the  coarsely  crystalline  lime- 
stone of  Grassy  Creek,  Pike  County,  Missouri,  and  Calhoun 
County,  Illinois,  are  distinct  formations  or  that  the  oolite  and 
limestone  are  one  formation,  while  the  Bowling  Green  and  the 
fossiliferous,  earthy,  magnesian  limestone  together  constitute 
another.  The  sections  taken  at  intervals  of  200  yards  along 
Grassy  Creek  in  the  western  part  of  sec.  24,  T.  54  N.,  R.  3  W., 
(Plate  VI),  show  very  well  the  variable  character  of  the  lower 
Silurian. 

Lithologically  the  Noix  oolite  presents  several  phases.  In 
the  bluff  south  of  Louisiana,  along  Grassy  and  Noix  creeks,  and 
along  a  branch  of  Turkey  Creek  about  1  mile  southwest  of  New 


"Savage,  T.  E.,  Stratigraphy  and  paleontology  of  the  Alexandrian  series  in  Illinois  and 
Missouri:     111.  State  Geol.  Survey  Bull.  23,  p.  77,  1917. 


26  MISSISSIPPI  VALLEY  AREA 

London  in  Ralls  County,  it  appears  as  a  gray,  partly  granular 
limestone  with  scattered  white  oolites  which  make  up  varying 
proportions  of  the  mass.  Elsewhere  along  the  bluff  region  of 
Mississippi  Valley,  it  appears  as  a  dense,  chocolate  colored,  al- 
most lithographic  rock,  massive  in  character  and  showing  a 
conchoidal  fracture.  In  this  rock,  the  oolites  are  best  seen  on  the 
weathered  surface  as  they  become  lighter  in  weathering,  but 
even  on  the  fresh  surface,  the  lighter  color  of  the  oolites  makes 
them  stand  out  from  the  darker,  almost  lithographic  ground 
mass  so  that  in  a  fresh  surface  the  oolites  appear  not  unlike  re- 
flections in  a  mirror. 

The  gray-colored  oolites  of  the  Noix  are  distinctive  and  once 
seen  can  never  be  confused  with  any  other  oolite  of  the  Mis- 
sissippi Valley.  They  are  almost  perfectly  rounded,  and  sur- 
prisingly uniform  in  size,  between  1/16  and  1/32  of  an  inch  in 
diameter. 

The  thickness  of  the  oolitic  beds  varies,  but  in  general,  the 
granular,  oolitic  phase  may  reach  a  thickness  of  10  feet  or  more, 
but  the  dense  phase  is  commonly  in  one  layer  not  more  than  4 
feet  thick  in  most  places. 

The  coarsely  granular  and  crystalline  phase  of  the  Cyrene 
is  massive  in  character,  light  gray  or  tinted  bluish  or  pink,  re- 
sembling greatly  the  Burlington  limestone  in  lithologic  character. 
This  phase  is  apparently  local  in  distribution,  and  may  represent 
erosion  remnants  of  a  once  more  widespread  formation,  or  it  may 
be  the  undolomitized  phase  of  the  Cyrene.  The  greatest  thick- 
ness observed  is  about  10  feet. 

The  typical  Cyrene  as  developed  in  the  vicinity  of  Bowling 
Green,  Edge  wood  and  Cyrene  in  Pike  County  and  in  north- 
western Lincoln  County,  Missouri,  is  brown  to  blue-gray,  earthy, 
magnesian  limestone  which  weathers  into  thin  beds,  but  is  massive 
when  fresh.  It  is  distinguished  from  the  overlying  Bowling 
Green  mainly  by  its  abundant  fossils  and  somewhat  more  earthy 
character.  The  greatest  thickness  of  this  horizon  is  about  20 
feet,  which  was  observed  in  northwestern  Lincoln  County  in  the 
east  bluff  of  Cuivre  River  south  of  the  road  in  the  NW.  Jl,  sec. 
22,  T.  51  N.,  R.  2  W. 

The  Bowling  Green  dolomite  representing  the  bulk  of  the 
Silurian  in  this  region,  is  well  exposed  throughout  the  area  of 
outcrop.  It  overlies  the  Cyrene  and  is  a  massive,  porous  dolo- 
mite, buff  to  gray  when  fresh,  but  weathering  to  a  uniform,' 
yellowish-brown  color.     The   pores   are   often  stained  red  with 


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STRATIGRAPHY  27 

iron  and  small,  dendritic,  black  markings  are  common.  Fossils 
are  scarce,  though  imperfect  casts  formed  by  the  leaching  out 
of  fossils  are  more  common.  The  thickness  of  the  Bowling  Green 
varies  greatly  from  place  to  place.  In  the  river  bluff  near 
Dameron  in  northeastern  Lincoln  County,  the  thickness  of 
Bowling  Green  is  not  less  than  70  feet;  northward  from  here,  the 
formation  though  varying  greatly  in  thickness,  gradually  becomes 
less  and  finally  pinches  out  so  that  it  is  missing  near  Louisiana; 
westward  in  Pike  County,  Missouri,  the  formation  also  thins, 
but  more  gradually,  as  the  westernmost  exposures  still  show  from 
10  to  20  feet  of  dolomite.  The  average  thickness  for  Pike  and 
northern  Lincoln  counties,  Missouri,  is  between  20  and  30  feet. 
In  Calhoun  County,  Illinois,  the  thickness  is  somewhat  more  uni- 
form and  averages  almost  30  to  35  feet  in  the  southern  portion 
but  becomes  gradually  thinner  northward.  In  Jersey  County, 
Illinois,  the  thickness  is  about  40  to  50  feet,  but  also  shows  a 
gradual  thinning  to  the  north  and  a  thickening  eastward  along 
the  southern  edge  of  the  county. 

SEXTON    CEEEK    LIMESTONE 

The  Sexton  Creek  limestone  which  is  not  so  widespread  as 
the  underlying  Bowling  Green  formation  is  best  developed  in 
the  vicinity  of  the  Mississippi  River  bluffs  (PI.  VII,  A).  In 
Missouri,  it  is  found  along  the  bluff  from  south  of  Dameron  in 
Lincoln  County  northward  to  the  vicinity  of  Clarksville,  but  no 
exposures  of  Sexton  Creek  are  found  at  any  distance  west  of  the 
river  in  Lincoln,  Pike,  or  Ralls  counties.  In  Illinois  good  ex- 
posures are  found  in  both  Illinois  and  Mississippi  River  bluffs. 
On  the  Illinois  side  of  Mississippi  River,  the  Sexton  Creek  is 
exposed  almost  continuously  from  2  miles  south  of  Gilead  in 
Calhoun  County  northward  to  Rockport  in  Pike  County.  Along 
Illinois  River  in  Calhoun  County,  the  Sexton  Creek  outcrops  as 
far  north  as  Hardin,  and  in  Jersey  County  it  is  exposed  in  the 
vicinity  of  Rosedale.  Eastward,  however,  in  the  vicinity  of 
Grafton,  no  exposures  of  the  typical  Sexton  Creek  occur. 

As  commonly  developed,  the  Sexton  Creek  is  a  hard,  dense, 
light  gray  limestone,  massive,  and  found  in  beds  up  to  2  feet  or 
more  thick.  Locally  it  is  almost  lithographic  or  has  layers  of 
more  coarsely  granular  rock.  In  the  vicinity  of  Fleasant  Hill, 
the  limestone  is  interlayered  with  one  or  more  layers  of  buff- 
colored  dolomite.  Locally,  as  at  Pleasant  Hill,  the  color  is 
mottled  red  and  green,  the  green  color  being  due  to  thin  irregular 


28  MISSISSIPPI  VALLEY  AREA 

partings  of  shaly  material  which  ramify  the  rock  in  all  directions 
and  cause  the  beds  to  weather  with  irregular  and  uneven  sur- 
faces. 

The  thickness  of  the  Sexton  Creek  is  extremely  variable, 
ranging  from  a  fraction  of  a  foot  to  50  feet,  with  variations  of 
from  5  to  20  feet  found  within  distances  of  100  yards.  Such 
extreme  variations  in  thickness  result  from  erosion  channels  made 
previous  to  the  deposition  of  Sexton  Creek  which  were  later 
filled  by  the  sediments  in  the  advancing  Sexton  Creek  sea.  The 
greatest  thickness  of  rock  is  found  south  of  Hamburg  in  Cal- 
houn County,  Illinois,  where  about  50  feet  of  Sexton  Creek  may 
be  seen,  but  north  and  south  of  here  the  thickness  becomes  less, 
so  that  the  average  thickness  in  Illinois  is  probably  less  than  15 
feet.  In  Missouri,  the  greatest  thickness  is  found  in  the  bluffs 
near  the  south  line  of  Pike  County,  and  while  old  erosion  chan- 
nels may  show  25  feet  or  more,  the  average  thickness  is  not  over 
10  feet. 

Devonian  System 
general  statement 

The  rocks  of  the  Devonian  system  in  this  region  consist 
mainly  of  limestones  with  minor  amounts  of  sandstone.  The 
Illinois  Geological  Survey  has  been  regarding  the  black  Sweet- 
land  Creek  shale,  which  overlies  the  Devonian  limestones  as  upper- 
most Devonian,  but  the  Missouri  Geological  Survey  assigns  the 
Grassy  Creek  shale,  which  corresponds  to  the  Sweetland  Creek 
shale,  to  the  basal  Mississippian  for  stratigraphic  reasons.13 
Although  the  Sweetland  Creek  shale  may  be  late  Devonian  in 
age,  it  is  much  more  closely  related  to  the  overlying  Mississippian 
than  the  underlying  Devonian  in  this  region,  and  will  therefore 
be  treated  with  the  Lower  Mississippian  in  this  report. 

In  Illinois,  the  Devonian  limestones  of  this  area  are  corre- 
lated with  the  Wapsipinicon-Cedar  Valley  limestones  of  Iowa.1416 
In  northeastern  Missouri,  the  Devonian  limestones  are  separated 
into  four  formations  as  follows:13 


"Branson,  E.  B.,  The  Devonian  of  Missouri:  Missouri  Bur.  of  Geology  and  Mines. 
Vol.  XVII,  2nd  ser.,  p.  5,  1923. 

"Weller,  Stuart,  Geology  of  southern  Calhoun  County:  111.  State  Geol.  Survey  Bull.  4, 
1907. 

"Savage,  T.  E.,  The  Devonian  formation  of  Illinois:  Amer.  Jour,  of  Science,  4th  Ser., 
Vol.  49,  p.  179,  1920. 


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STRATIGRAPHY  29 

Snyder  Creek  shale 

Callaway  limestone 

Mineola  limestone 

Cooper  limestone 

Of  these  formations,  all  except  the  Snyder  Creek  shale  are 
present  in  this  area.  Because  of  the  difference  in  nomenclature 
and  in  the  absence  of  correlations  showing  the  equivalency  of  the 
Devonian  in  Illinois  and  Missouri,  the  limestones  of  this  age  will 
be  treated  as  a  unit  and  discussed  as  the  Devonian  limestone. 

DISTRIBUTION 

Like  the  exposures  of  the  older  rocks,  the  Devonian  outcrops 
are  confined  to  the  flanks  of  the  Cap-au-Gres  uplift  and  were  ob- 
served only  in  southern  Marion,  Pike,  Ralls,  and  Lincoln  counties, 
in  Missouri,  and  Calhoun  and  southwestern  Jersey  counties  in 
Illinois.  Throughout  Pike  and  Lincoln  counties,  Missouri,  and 
Calhoun  and  Jersey  counties,  Illinois,  the  Devonian  reaches  a 
thickness  of  20  feet  in  a  few  places,  and  probably  averages  less 
than  10  feet.  It  is  patchy  in  its  distribution  and  is  missing  en- 
tirely over  wide  areas.  Thus  in  the  immediate  vicinity  of  Mis- 
sissippi River  valley  between  Quincy,  Illinois,  and  Clarksville, 
Missouri,  no  Devonian  is  present  although  the  proper  horizon 
is  exposed  for  several  miles  in  both  bluffs  of  the  river. 

In  northern  Ralls  and  western  Marion  counties,  Missouri, 
however,  the  Devonian  thickens  rapidly  and  reaches  a  maximum 
thickness  of  not  less  than  100  feet  in  northwestern  Ralls  County. 
This  increase  in  thickness  of  the  Devonian  in  Ralls  County  is  the 
result  of  pre-Devonian  erosion  of  lower  formations  and  the  subse- 
quent deposition  of  Devonian  limestones  on  this  slope  which 
marked  an  early  shoreline  of  the  invading  Devonian  sea.  The 
relation  of  the  Devonian  to  earlier  and  later  formations  is  shown 
in  the  accompanying  generalized  sketch  (PL  VIII). 

Similar  relations  hold  from  north  to  south  as  from  west 
to  east.  The  distribution  and  stratigraphic  relations  of  the 
Devonian  point  to  a  northern,  or  possibly  western,  Devonian 
basin  from  which  the  seas  transgressed  upon  the  Ozark  highland. 

CHARACTER  OF  THE  ROCK  AND  STRATIGRAPHIC  RELATIONS 

The  best  exposures  of  the  Devonian  limestones  are  in  Ralls 
County,  Missouri,  in  the  vicinity  of  Flint  Hill  church  in  sec.  28, 


30        <  MISSISSIPPI  VALLEY  AREA 

T.  56  X..  R.  4  W.  about  three  miles  northeast  of  New  London, 
and  westward  along  all  the  larger  tributaries  north  of  Salt  River 
as  far  west  as  Shiel  in  sec.  20,  T.  56  X..  R.  6  W.  In  Marion 
County.  Devonian  rocks  were  observed  only  in  sees.  8.  9  and  22, 
T.  57  X.,  R.  7  W.,  near  the  junction  of  Sees  Creek  and  the  south 
fork  of  North  River. 

The  character  of  these  Devonian  limestones  varies  some- 
what from  place  to  place.  In  the  vicinity  of  Flint  Hill  church 
it  rests  on  either  Maquoketa  shale  or  X'oix  oolite.  Here  the 
basal  layer  of  the  Devonian  is  compact,  gray,  granular  limestone 
containing  pebbles  and  boulders  of  Xoix  oolite  and  fragments  of 
chert,  and  is  overlain  by  about  50  feet  of  dense,  gray  to  blue, 
finely  crystalline  to  granular  limestone,  many  layers  of  which 
show  a  brecciated  or  conglomeratic  character  on  the  weathered 
surface.  In  the  lane  back  of  the  house  in  the  east  central  por- 
tion of  sec.  29.  T.  56  X.,  R.  4  W.,  sandstone  fragments  and  slabs 
were  observed  which  apparently  came  from  the  lower  portion  of 
the  formation.  Some  of  the  higher  limestone  layers  exhibited 
intricate  cross  bedding  and  a  tendency  to  split  into  thin  layers 
one  inch  or  less  thick. 

At  the  east  side  of  the  road  near  the  ravine  in  the  south  cen- 
tral part  of  sec.  24.  T.  56  X"..  R.  5  W.,  the  Devonian  is  separated 
from  the  Kimmswick  by  strata  less  than  20  feet  in  thickness. 
This  is  overlain  by  several  feet  of  only  partially  exposed,  gray, 
dense,  conglomeratic  limestone,  upon  which  lies  8-12  feet  of  gray 
sandstone,  generally  soft  and  friable  but  locally  cemented  into 
hard,  massive  sandstone.  The  grains  of  the  sandstone  are  well 
rounded  and  frosted,  not  unlike  grains  of  the  St.  Peter  sandstone, 
but  are  somewhat  smaller.  The  color  of  the  sandstone  is  gener- 
ally gray  or  yellowish,  but  locally  the  weathered  surface  may  be 
brown.  The  sandstone  is  in  turn  overlain  by  about  40  feet  of 
dense,  line-grained  limestone  with  few  or  no  fossils.  About  a 
mile  north  of  the  ravine  in  sec.  24.  T.  56  X..  R.  5  W.,  there  is 
exposed  in  a  road  cut  above  the  Devonian  limestone  about  6 
feet  of  black  fissile  shale.  The  limestone  beneath  the  shale 
is  a  finely  granular,  brown  dolomite,  but  farther  down  the  ravine 
to  the  east,  the  dolomite  gives  way  to  the  dense,  gray,  brecciated 
phase.  Good  exposures  of  the  dense,  gray,  brecciated  limestone 
with  sandstone  near  the  base  may  also  be  seen  in  the  ravines  in 
sees.  22  and  23  of  T.  56  X.,  R.  5  W.  Along  the  creek  in  sec.  28, 
T.  56  X.,  R.  6  W.,  there  are  also  good  exposures  of  the  Devonian 
limestone,    but    no   sandstone   member   is   present    in   the   lower 


STRATIGRAPHY  31 

portion  of  the  section  and  about  50  feet  of  dense,  massive,  some- 
what brecciated  limestone  rests  on  the  Kimmswick  limestone. 
Above  the  dense,  brecciated  rock,  there  is  a  20-foot  layer  of  mas- 
sive, somewhat  earthy  and  finely  granular,  dolomitic  rock  which 
is  overlain  by  about  30  feet  of  more  variable  limestone  in  which 
non-brecciated,  dense  limestone  is  interbedded  with  earthy  to 
granular  layers.  These  upper  beds  are  abundantly  fossiliferous 
in  which  respect  they  differ  widely  from  the  very  slightly  fossil- 
iferous lower  portion.  Also,  the  upper  30  feet  appears  to  be 
separated  from  the  underlying  massive  layer  by  an  unconformity 
and  the  basal  layer  is  locally  conglomeratic.  The  contact  of  the 
underlying  massive  layer  and  the  dense,  brecciated  limestone  is 
also  irregular  and  it  is  possible  that  detailed  stratigraphic  work 
will  show  the  Devonian  limestone  in  northern  Ralls  County  to 
consist  of  several  distinct  members  or  even  formations. 

Along  the  road  north  of  New  London  in  sec.  13,  T.  56  N., 
R.  5  W.,  the  Devonian  limestones  are  overlain  by  about  10  feet 
of  black  shale  which  is  in  turn  overlain  by  the  Louisiana  lime- 
stone. 

The  Devonian  limestone  on  the  Illinois  side  of  the  Mississippi 
and  in  Pike  and  Lincoln  counties,  Missouri,  rests  in  most  places 
on  the  Silurian.  In  the  vicinity  of  the  Cap-au-Gres  fault  in 
Lincoln  County,  Missouri,  it  overlaps  the  Silurian  and  rests  upon 
the  Maquoketa  shales.  Northward  in  the  vicinity  of  Bowling 
Green  and  Louisiana  in  Pike  County,  the  black  shale  rests  on  the 
Silurian  and  no  Devonian  limestones  are  present,  so  that  these 
Devonian  limestones  in  the  Missouri  portion  of  the  area  exam- 
ined are  limited  to  a  rather  small  area,  including  only  Lincoln 
County  and  southeastern  Pike  County. 

Eastward  across  the  Mississippi,  the  same  Devonian  lime- 
stone appears  in  the  bluff  of  Calhoun  County  and  extends  from 
Llamburg  southward  to  within  six  miles  of  the  fault.  North  of 
Hamburg,  the  Devonian  is  missing  and  the  Kinderhook  shales 
rest  on  the  Silurian.  On  the  east  side  of  Calhoun  County,  the 
Devonian  again  appears  in  Illinois  River  bluff  from  Hardin  where 
it  dips  beneath  younger  formations  southward  to  the  village  of 
Meppen,  but  south  of  there  the  Kinderhook  shale  rests  on 
Silurian  limestones.  Eastward  across  Illinois  River  the  De- 
vonian again  appears  in  the  bluff  and  is  present  wherever  strata 
of  the  proper  stratigraphic  horizon  are  exposed,  which  is  from  the 
vicinity  of  Nutwood  to  Grafton. 


32 


MISSISSIPPI  VALLEY  AREA 


The  Devonian  of  Illinois  and  south  of  Ralls  County,  Mis- 
souri, is  predominantly  a  very  fossiliferous,  earthy,  dolomitic 
limestone,  but  locally  as  in  the  vicinity  of  Nutwood  in  Jersey 
County,  and  in  the  bluff  in  the  vicinity  of  Hardin  in  Calhoun 
County,  and  in  Lincoln  County,  Missouri,  it  grades  upward  into 
a  coarsely  granular,  gray  limestone.  The  dolomitic  beds  are 
gray  and  earthy  on  the  fresh  surface,  but  the  weathered  face  is 
brown  and  in  the  absence  of  fossils,  is  distinguished  with  diffi- 
culty from  the  underlying  dolomite  of  the  Silurian,  where  the 
light  gray  limestone  of  the  Sexton  Creek  formation  is  absent. 
The  basal  layers  of  the  Devonian  are  locally  sandy  and  in  some 
places,  as  in  Calhoun  and  Jersey  counties,  thin  layers  of  pure 
quartzose  sandstone  carrying  the  same  fossils  as  the  underlying 
limestone  may  be  found.  The  thickness  of  the  formation  varies 
from  place  to  place,  but  the  maximum  observed  in  outcrop  is 
less  than  20  feet,  and  near  Grafton  it  is  less  than  5  feet. 

Mississippian  System 

lower  mississippian  sub-system 

With  the  exception  of  small  areas  of  Pennsylvanian  rocks  and 
a  few  scattered  remnants  of  Tertiary  gravels,  the  consolidated 
rocks  exposed  in  the  remaining  area  are  lower  Mississippian  in 
age.  These  Lower  Mississippian  rocks  are  separated  into  sev- 
eral series  which  are  further  subdivided  into  formations  as  shown 
in  the  following  table: 


Subdivisions  of  the  Lower  Mississippian  strata 


Sub- 
system 

Group  or  Series 

Formation 

"ft 

Meramec 

Ste.  Genevieve 
St.  Louis 
Spergen 
Warsaw 

ft 
'ta 

w 

*«3 

W 

Osage 

Keokuk 
Burlington 
Fern  Glen 

U 

o 

Kinderhook 

Chouteau 
Hannibal 
Louisiana 
Sweetland  Creek  (Grassy  Creek) 

STRATIGRAPHY  33 


K1NDERHOOK    SERIES 


Sweetland  Creek  (Grassy  Creek)  shale. — In  Missouri  north  of 
a  line  extending  east  and  west  through  a  point  several  miles  south 
of  Louisiana,  Pike  County,  a  black,  fissile  shale  containing  abun- 
dant sporangites  occurs  at  the  base  of  the  Kinderhook.  As 
observed  at  most  outcrops,  the  basal  portion  of  the  shale  is  sandy 
and  locally  becomes  a  thin  layer  of  sandstone  containing  copro- 
lites  and  fish  teeth.  The  main  bulk  of  the  shale  is  a  massive, 
thinly  laminated  shale  which  is  black  when  fresh,  but  weathers 
to  a  gray  or  blue  gray  color.  Locally,  however,  the  black  fissile 
character  is  not  developed  and  the  mass  of  shale  is  blue-gray. 
The  upper  portion  is  often  greenish  in  color  and  lacks  the  finely 
laminated  structure  of  the  black.  This  shale  is  well  exposed 
in  the  river  bluff  in  the  vicinity  of  Louisiana  where  it  rests  on 
the  Noix  oolite  and  farther  north  on  the  Maquoketa.  It  is  also 
exposed  along  Grassy  Creek  west  of  Louisiana. 

In  Ralls  County,  Missouri,  exposures  are  found:  (1)  in  the 
river  bluffs  in  the  vicinity  of  Saverton;  (2)  at  the  road  cut  in  the 
southern  part  of  sec.  13,  T.  56  N.,  R.  5  W.;  (3)  where  the  road 
crosses  a  branch  of  Turkey  Creek  in  sec.  2  about  1  Yi  miles  south- 
west of  New  London;  (4)  along  Cedar  Creek  in  the  southern 
portion  of  sec.  28,  T.  56  N.,  R.  6  W.;  and  (5)  near  the  mouth  of 
Brush  Creek  in  sec.  30,  T.  55  N.,  R.  4  W.  At  the  last  named  lo- 
cality the  black  shale  is  more  sandy  and  contains  several  well 
defined  layers  of  sandstone  which  contain  abundant  fish  remains. 

Section  near  mouth  of  Brush  Creek  in  sec.  SO,  T.  55  N.,  R.  4  W. 

Thickness 

Ft.  In. 

Limestone,  Louisiana 10  — 

Shale,  calcareous —  4 

Shale,  black  laminated 4-5  — 

Sandstone,  fine,  gray,  soft  and  friable 3  — 

Shale,  dark,  weathers  gray 1 3^-2  — 

Sandstone,  conglon  eratic  (mottled  green  from  included  shale).  .        1  — 

Shale,  gray,  calcareous,  massive  layer    (Maquoketa?) 4  — 

In  Marion  County  good  exposures  of  the  black  shale  were 
seen  at  the  ravine  in  the  SW.  \i  sec.  18,  T.  57  N.,  R.  7  W.,  also 
along  Sees  Creek  in  sec.  15,  T.  57  N.,  R.  7  W.,  and  in  sec.  29, 
T.  57  N.,  R.  6  W.  The  character  of  the  shale  in  Marion  County 
is  similar  to  that  previously  described,  but  the  variation  in  the 
amount  of  the  black  laminated  layers  is  greater. 


34  MISSISSIPPI  VALLEY  AREA 

Across  the  Mississippi  in  Illinois,  the  black  shale  is  well  ex- 
posed in  the  river  bluffs  in  the  vicinity  of  Rockport  and  Atlas  in 
Calhoun  County,  but  becomes  thin  southward  and  is  not  present 
at  and  south  of  Hamburg.  Along  the  Illinois  River  bluff,  the 
black  shale  is  well  exposed  just  south  of  Bedford  in  Pike  County, 
but  farther  south  as  near  Hardin  in  Calhoun  County  where  the 
horizon  of  the  black  shale  appears,  no  shale  is  present  and  the 
Louisiana  limestone  rests  directly  on  Devonian  limestone. 

The  black  shale  is  not  well  developed  in  Jersey  County, 
but  has  been  observed  locally  as  near  the  mouth  of  the  ravine 
where  the  powder  plant  is  located  east  of  Grafton. 

The  thickness  of  the  black  shale  is  variable.  On  the  Mis- 
souri side  in  the  vicinity  of  Louisiana,  it  is  from  4  to  6  feet,  along 
Grassy  Creek  about  5  to  10  feet,  farther  north  in  Ralls  County  10 
to  20  feet,  and  in  Marion  County  as  much  as  40  feet  of  black  shale 
is  revealed.  In  Illinois  similar  variations  are  found.  Near 
Rockport  and  Atlas,  50  feet  or  more  can  be  referred  to  the  black 
shale,  though  neither  the  overlying  Louisiana  limestone  or  under- 
lying formations  are  present.  It  may  be  said  that  the  black  shale 
shows  increased  thickness  to  the  north  and  east,  the  greatest 
increase  being  toward  the  center  of  the  Illinois  basin.  West- 
ward the  formation  changes  in  character  and  becomes  more  sandy 
and  grades  into  sandstone. 

The  relation  of  the  black  shale  to  the  underlying  forma- 
tions is  distinctly  unconformable,  for  the  black  shale  rests 
locally  on  the  Maquoketa  shale,  Silurian  or  Devonian  limestone. 
The  break  between  the  overlying  Louisiana  limestone  and  black 
shale  is  not  so  pronounced  and  no  distinct  evidence  of  uncon- 
formity is  observable  where  both  are  present.  Southward, 
however,  as  in  southern  Calhoun  and  Jersey  counties,  Illinois, 
and  in  southern  Pike  County,  the  Louisiana  overlaps  the  black 
shale  and  rests  directly  on  the  Devonian  (PL  IX,  A). 

Louisiana  limestone. — The  Louisiana  limestone  is  much 
more  local  in  its  distribution  than  any  of  the  previously  described 
formations.  It  is  best  exposed  in  the  Mississippi  River  bluff 
between  Louisiana  and  Hannibal,  Missouri,  where  it  reaches  a 
thickness  of  about  60  feet.  It  continues  northwest  with  only 
a  slight  diminution  in  thickness,  but  becomes  thinner  rapidly 
to  the  southwest  and  east. 

The  limestone  is  well  exposed  in  Marion  County  in  the  river 
bluff  at  Hannibal  and  along  Sees  Creek,  Lick  Creek  and  South 
River  in  T.  57  N.,  Rs.  6  and  7  W.     It  outcrops  also  in  Ralls 


Illinois  State  Geological  Survey. 


Bulletin  No.  45,  Plate  IX. 


A.  Unconformable  contact  between  the  Devonian  and  the  overlying  Louisiana  limestone 
in  quarry  about  3  miles  south  of  Hardin.  Note  shaly  layer  at  contact  indicated  by 
hammer. 


B.     Contact  of  Hannibal  shale  and  Chouteau-Burlington  limestone  near  Hardin  in  Calhoun 

County,  Illinois. 


STRATIGRAPHY  35 

County,  but  westward  from  the  bluffs  it  is  much  thinner,  being 
less  than  15  feet  thick  at  its  most  western  outcrops.  In  Pike 
County  it  is  prominent  in  the  river  bluffs,  but  becomes  thinner 
rapidly  to  the  west  and  south,  finally  disappearing  apparently 
as  no  exposures  have  been  observed  in  Lincoln  County. 

Eastward  in  Illinois  the  Louisiana  is  much  thinner.  In  the 
vicinity  of  Hamburg  in  Calhoun  County,  it  is  about  5  feet  thick 
and  gradually  disappears  southward.  Northward  it  is  present 
as  far  as  the  Pike  County  line,  but  no  good  exposures  of  Louisiana 
have  been  observed  any  farther  north.  On  the  east  side  of  Cal- 
houn County,  an  8-foot  outcrop  of  Louisiana  appears  in  the 
bluff  just  north  of  Hardin,  and  continues  southward  with  a 
gradual  decrease  in  thickness  until  it  pinches  out  entirely  about 
4  miles  south.  The  Louisiana  limestone  does  not  appear  again 
north  of  Hardin  though  its  horizon  is  exposed  near  the  north 
line  of  the  county  and  south  of  Bedford  in  Pike  County.  Across 
Illinois  River  in  Jersey  County,  several  feet  of  Louisiana  lime- 
stone are  exposed  in  the  vicinity  of  Nutwood,  but  it  does  not 
appear  in  the  bluffs  near  Grafton. 

Where  best  developed,  the  Louisiana  is  a  dense,  practically 
lithographic  limestone  occurring  in  2  to  6-inch  layers  separated 
by  thin  partings  of  shale.  The  rock  weathers  light  gray  and 
the  average  bluff  exposure  resembles  greatly  a  wall  of  masonry. 
The  fracture  is  conchoidal  and  the  rock  gives  forth  a  ringing 
sound  when  struck  with  the  hammer.  Locally,  however,  the 
upper  beds  may  be  dolomitic  and  the  rock  then  takes  on  a  buff 
or  brown,  sandy  appearance.  Elsewhere,  thin  layers  of  brown 
dolomite  alternate  with  gray  limestone  layers  causing  the  bluff 
exposures  to  appear  banded.  Where  the  upper  portion  is  pre- 
dominantly dolomitic  it  often  contains  numerous  calcite  geodes 
varying  in  size  from  less  than  an  inch  to  several  inches  in  diam- 
eter. In  general,  the  variations  in  the  character  of*  the  rock 
are  confined  to  the  upper  half  of  the  formation  and  the  lower 
portion  is  very  similar  throughout  the  region  of  outcrop.  At 
most  exposures  there  is  found  below  the  limestone  non-laminated, 
massive,  blue-gray  shale  which  reaches  a  thickness  of  several 
feet  near  Louisiana,  but  at  most  exposures  may  be  less  than  a  foot. 

Hannibal  shale. — In  the  vicinity  of  Hannibal,  Missouri,  the 
Louisiana  limestone  is  overlain  by  about  60  feet  of  greenish, 
sandy  and  generally  non-laminated  shale.  Near  Hannibal  and 
to  the  north  and  west  in  Marion  and  Ralls  counties,  the  shale  is 
predominantly  sandy  in  the  upper  portion,  and  was  termed  "Ver- 


36  MISSISSIPPI  VALLEY  AREA 

micular  Sandstone"  by  the  older  geologists  because  of  its  sandy 
character  and  the  presence  of  small,  ramifying,  tubular  holes 
filled  with  softer,  earthy  material  than  the  surrounding  mass. 
Such  holes  are  considered  to  be  worm  borings.  Southward  as  in 
southern  Pike  and  Lincoln  counties,  Missouri,  the  shale  becomes 
less  sandy  and  thinner,  so  that  in  Lincoln  County,  the  shale  is 
only  about  40  feet  thick  and  locally  less.  Still  farther  south  in 
Missouri  along  Missouri  River,  just  west  of  Hamburg  in  St. 
Charles  County,  the  horizon  of  the  Hannibal  shale  shows  the 
overlying  Chouteau  resting  on  6  feet  of  pure,  medium-grained, 
massive  sandstone,  which  is,  in  turn,  underlain  by  about  A1/^ 
feet  of  gray,  sandy,  fossiliferous  oolite.  At  Grafton  in  Jersey 
County,  Illinois,  about  1  foot  of  fossiliferous,  sandy  oolite  occurs 
at  the  base  of  the  Hannibal,  and  farther  north  at  Hamburg  in 
Calhoun  County,  the  base  of  the  Hannibal  shale  consists  of  dense, 
siliceous  limestone  interbedded  with  sandy  shale.  At  this  hori- 
zon, fossiliferous  oolite  called  "Hamburg  oolite,"  the  fauna  of 
which  is  described  by  Weller15,  is  intercalated  locally  with  the 
siliceous  limestones  and  shales.  Fossiliferous,  oolitic  limestone 
has  been  noted  at  this  horizon  on  the  east  side  of  Calhoun  County 
in  the  road  cut  along  the  bluff  just  south  of  Cliffdale.  Farther 
north  in  Pike  County,  Illinois,  there  is  exposed  in  the  creek  bed 
in  the  NW.  K,  sec.  25,  T.  6  S.,  R.  5  W.,  about  1  mile  southwest 
of  Rockport,  6  feet  of  massive,  oolitic  conglomerate  consisting 
of  pebbles  of  lithographic  Louisiana  limestones  in  a  matrix  of 
oolites. 

The  main  body  of  the  Hannibal  shales  in  Illinois,  as  in 
Missouri,  is  thinnest  to  the  south  and  becomes  gradually  thicker 
northward.  Thus  near  Grafton  in  Jersey  County  and  in  south- 
ern Calhoun  County  it  is  between  30  and  40  feet,  but  near  the 
north  line  of  Calhoun,  is  between  80  and  100  feet,  this  interval 
continuing  into  Pike  County  where  the  Hannibal  shale  rests  on 
the  Sweetland  Creek  so  that  the  contact  is  not  everywhere  ob- 
servable. The  character  of  the  shale  likewise  changes  from  south 
to  north.  In  the  southern  portion,  the  shale  is  mostly  non- 
laminar  with  a  structure  like  earthy  cement  rock.  Farther 
north  it  becomes  increasingly  siliceous;  in  northern  Pike  County, 
Illinois,  the  upper  portion  is  a  massive  calcareous  fine-grained 
sandstone,  in  places  abundantly  fossiliferous  capped  by  from  1 
to  15  feet  of  dense,  siliceous  limestone  in  the  vicinity  of  Kinder- 


i»Weller,  Stuart,  Trans.  St.  Louis  Acad.  Scl.,  vol.  16.  No.  7,  p.  465. 


STRATIGRAPHY  37 

hook  and  northward.  The  limestone  shows  a  gradual  thicken- 
ing north  from  Kinderhook  and  at  Fall  Creek  about  10  feet  of 
sandy  dolomite,  lithologically  similar  to  that  below  the  limestone 
occurs  above  the  limestone. 

At  these  northernmost  exposures,  the  Hannibal  shale  is 
immediately  overlain  by  Burlington  limestone  (PI.  IX,  B)  which 
is  locally  conglomeratic  at  the  base  with  pebbles  of  the  siliceous 
limestone  in  a  matrix  of  the  coarsely  granular  limestone. 

Chouteau  limestone. — In  the  southern  portion  of  the  area  in 
southern  Pike,  Lincoln  and  St.  Charles  counties,  Missouri,  and 
in  Calhoun  and  Jersey  counties,  Illinois,  the  Hannibal  shales  are 
overlain  by  a  limestone  which  is  referred  to  as  the  Chouteau. 

The  limestone  is  somewhat  variable  in  character,  but  in 
most  exposures  appears  as  a  dense,  tough  and  somewhat  earthy 
limestone  with  a  few  scattered  chert  nodules.  The  weathered 
surface  becomes  gray  in  color  and  is  often  characterized  by  a 
knotty  appearance  brought  about  by  softer,  shaly  portions 
weathering  away  from  more  resistant  cores.  The  more  shaly 
layers  have  a  speckled  appearance,  caused  by  scattered  faces  of 
crystalline  calcite  in  a  dense  drab  background.  Small  calcite 
geodes,  seldom  more  than  an  inch  in  diameter,  are  prominent 
in  the  soft,  earthy  and  dolomitic  phase.  Locally,  as  in  south- 
ern Calhoun  County,  the  basal  layer  may  be  granular  and  in 
Jersey  County,  the  topmost  beds  are,  in  places,  lithographic  in 
texture. 

The  Chouteau  is  well  exposed  in  Missouri  River  bluffs  east 
of  Hamburg  in  St.  Charles  County,  and  in  Lincoln  County, 
Missouri;  in  Illinois  in  the  river  bluffs  of  Calhoun  County  in  the 
vicinity  of  Hardin,  and  in  bluffs  of  southwestern  Jersey  County. 
The  limestone  in  Lincoln  County,  Missouri,  southern  Calhoun 
and  Jersey  counties,  Illinois,  is  from  40  to  60  feet  thick,  but  thins 
northward  gradually  to  Calhoun  County,  Illinois,  and  Pike 
County,  Missouri,  north  of  which  it  disappears. 

The  Chouteau  appears  to  be  conformable  with  the  underlying 
shale  and  the  interval  occupied  by  both  remains  practically  con- 
stant, because  as  the  limestone  thins  northward  the  shale  in- 
creases in  thickness.  In  Calhoun  and  Pike  counties,  Illinois, 
the  approximate  contact  of  the  overlying  Osage  group  and  the 
Chouteau  is  marked  by  a  soft,  dolomitic  layer  which  in  the 
bluff  face  is  usuallv  weathered  back  several  feet. 


38  MISSISSIPPI  VALLEY  AREA 


OSAGE    SERIES 


The  Osage  series,  consisting  mainly  of  crinoidal  limestones 
with  only  minor  amounts  of  shale,  is  best  exposed  in  the  bluffs 
along  Mississippi  and  Illinois  rivers,  and  in  western  Ralls,  Pike 
and  Lincoln  "counties  and  central  St.  Charles  county,  Missouri. 
The  divisions  are  given  in  the  table,  page  32. 

Fern  Glen  formation. — The  Fern  Glen  formation  has  been 
recognized  only  in  the  vicinity  of  Chautauqua  and  Grafton  in 
Jersey  County,  Illinois,  but  the  red  and  green  shales  and  shaly 
limestones  which  form  so  conspicuous  a  feature  of  the  formation 
at  its  type  locality  are  almost  wholly  lacking.  At  Chautauqua 
a  25  to  30-foot  massive  layer  of  granular  limestone  free  from 
chert  is  found  above  the  dense  limestone  of  the  Chouteau  and 
is  overlain  by  about  25  feet  of  shaly  limestone,  predominantly 
greenish  in  color  but  locally  pink  or  red,  containing  thin  layers 
or  nodules  of  blue  or  green  chert.  Above  this  shaly  limestone 
lies  the  white,  coarsely  granular,  crinoidal  limestone  of  the 
typical  Burlington.  A  somewhat  similar  section  occurs  at  Graf- 
ton, but  the  shaly  phase  is  even  less  pronounced,  the  shale  being 
limited  to  thin  partings  between  layers  of  granular  limestone. 
This  formation  is  undoubtedly  present  in  St.  Charles  and  Lin- 
coln counties,  Missouri,  but  the  horizon  was  not  examined  in 
those  counties.  Undoubtedly  the  Fern  Glen  continues  north- 
ward from  Grafton,  but  assumes  more  and  more  the  character 
of  the  Burlington,  and  can  be  distinguished  only  by  its  fossils. 
Like  the  Chouteau,  it  thins  to  the  northward  and  is  certainly 
not  present  far  north  of  Kinderhook. 

Burlington-Keokuk  limestone. — Above  the  Fern  Glen,  coarse- 
ly granular,  crinoidal  limestone  of  the  Burlington-Keokuk  occurs 
in  great  thickness.  In  the  northern  part  of  the  area  this  mass 
of  limestone  is  readily  divisible  into  two  formations  on  the  basis 
of  the  fossils  and  lithology,  but  in  the  southern  part  there  is  no 
apparent  break,  and  while  both  formations  are  present,  it  is 
practically  impossible  to  find  a  line  of  separation. 

The  Burlington-Keokuk  limestone  is  well  exposed  along 
the  bluffs  on  the  Illinois  side  from  east  of  Grafton  northward 
to  Dallas  in  Hancock  county  and  also  outcrops  along  most  of  the 
creeks  in  southern  Pike  and  Calhoun  counties.  In  Missouri,  it 
shows  in  the  bluff  from  Kissinger,  Pike  County,  northward  to 
the  north  line  of  the  State  and  is  exposed  along  most  of  the  creeks 


STRATIGRAPHY  39 

in  central  St.  Charles  and  in  western  Lincoln  (PI.  X,  A),  Pike, 
Ralls,  and  Marion  counties. 

The  Burlington  limestone  is  typically  a  massive,  coarsely 
granular,  light  gray,  crinoidal  limestone.  Bedding  planes  are 
usually  indistinct  in  fresh  exposures,  but  where  weathered,  the 
rock  shows  beds  of  6  inches  to  8  feet  thick.  The  details  of  the 
section  vary  from  place  to  place,  and  locally  there  are  inter- 
calated with  the  gray  limestone  varying  amounts  of  brown, 
dolomitic  rock.  Chert,  abundant  especially  in  the  upper  por- 
tion, occurs  as  irregular  layers  and  nodules  which  may  be  thin 
plates  or  masses  a  foot  or  more  thick. 

The  thickness  of  the  Burlington,  including  the  cherty 
transition  beds,  is  about  100  feet.  The  total  thickness  of  the 
Osage,  therefore,  is  about  160  feet  in  the  northern  portion  and 
between  250  and  300  feet  in  Jersey  County,  but  the  increase 
to  the  south  is  due  mainly  to  the  presence  of  the  Fern  Glen 
formation,  the  Burlington-Keokuk  itself  remaining  fairly  con- 
stant. 

In  the  northern  part  of  the  region  where  the  Keokuk  is 
recognized  as  a  distinct  formation,  it  consists  of  layers  of  rather 
coarsely  granular  limestone  6  inches  to  6  feet  thick,  separated 
by  shaly  layers  up  to  two  feet  thick.  The  texture,  while  granu- 
lar, is  finer  than  the  Burlington,  and  less  crinoidal,  and  the  color 
is  usually  a  bluish-gray  as  compared  with  the  light  gray  or  white 
color  of  the  Burlington.  Chert,  as  thin  platy  layers  and  nodules, 
is  abundant  near  the  top  of  the  formation,  and  again  at  the 
base  where  an  interval  of  about  30  feet  of  very  cherty  limestone 
marks  the  transition  of  the  Keokuk  into  the  Burlington.  The 
large,  middle  portion  of  the  formation,  however,  is  relatively  free 
from  chert.  Southward,  the  shale  intervals  become  progressively 
smaller  and  the  limestones  more  crinoidal  and  more  coarsely 
grained  until  it  becomes  difficult  to  distinguish  the  two.  The 
thickness  of  the  Keokuk  exclusive  of  the  lower  30  feet  of  cherty 
limestone  is  between  60  and  80  feet,  an  interval  surprisingly 
constant  for  Clark  and  Lewis  counties,  Missouri,  and  Hancock 
County,  Illinois. 

MERAMEC    SERIES 

The  Meramec  series,  which  is  divided  into  several  formations 
as  shown  in  the  table  (page  32),  outcrops  in  the  vicinity  of  the 
Mississippi  River  bluffs,  in  Lewis,  Clark,  southern  Lincoln  and 


40  MISSISSIPPI  VALLEY  AREA 

St.  Charles  counties,  Missouri,  and  in  Hancock,  Adams,  northern 
Pike  and  Jersey  counties,  Illinois,  and  though  it  outcrops  mainly 
in  the  vicinity  of  the  river  bluffs  it  underlies  most  of  the  counties 
mentioned. 

In  this  preliminary  study  no  break  was  observed  between 
the  Meramec  and  Osage  series  in  this  area,  nor  was  any  con- 
vincing evidence  found  of  a  break  between  the  different  forma- 
tions of  the  Meramec  series. 

Warsaw-Spergen  formations. — The  Warsaw  and  Spergen 
are  recognized  as  distinct  formations  over  most  of  the  area,  but 
it  is  extremely  difficult,  if  not  impossible,  at  most  localities 
to  say  where  one  begins  and  the  other  ends.  In  the  northern 
part  of  the  region  these  formations  are  dominantly  shale  with 
only  minor  amounts  '  of  limestone,  except  locally,  but  in 
the  southern  part  they  become  increasingly  calcareous  con- 
sisting mainly  of  limestone  in  the  upper  portion,  but  retaining 
the  shaly  phase  in  the  lower  portion.  This  horizon  is  probably 
the  most  variable  in  the  whole  Lower  Mississippian  section,  and 
no  two  sections  taken  more  than  half  a  mile  apart  show  much 
agreement  in  lithologic  details. 

East  of  Niota  in  the  NE.  %,  sec.  17,  T.  7  N.,  R.  7  W.,  in 
northern  Hancock  County,  an  old  abandoned  quarry  exposes  a 
vertical  face  50  to  60  feet  high,  which  at  the  top  shows  about  10 
feet  of  cross-bedded,  gray  limestone  that  splits  readily  into  thin 
layers  along  the  planes  of  the  cross-bedding.  Below  this  cross- 
bedded  limestone  is  about  40  feet  of  massive,  porous,  brown 
dolomite*  consisting  mainly  of  Bryozoa,  and  occurring  in  layers 
up  to  several  feet  thick.  A  short  distance  down  stream  the 
granular,  cherty  limestone  of  the  Keokuk  is  found  at  an  ele- 
vation not  more  than  20  feet  below  the  dolomite  of  the  quarry. 
In  the  region  west  of  here  as  shown  at  the  abandoned  quarry 
near  the  center  of  sec.  11,  T.  7  N.,  R.  8  W.,  there  occurs  below 
the  St.  Louis  a  3  to  4-foot  layer  of  dolomite  containing  many 
small,  scattered  quartz  grains  about  the  size  of  a  pin  head.  This 
is  underlain  by  3  to  5  feet  of  bluish,  calcareous  shale,  below  which 
is  a  20-foot  ledge  of  finely  crystalline  dolomite  consisting 
mainly  of  Bryozoan  fragments,  and  this  ledge  is  in  turn  underlain 
by  shale.     At  Warsaw  (PI.  X,  B)  the  following  section  occurs: 


Illinojs  State  Geological  Survey. 


Bulletin  No.  45,  Plate  X. 


A.  Structural  slope  of  steeply  dipping  Burlington-Chouteau  limestone  on  the  west  limb 
of  the  Lincoln  fold  about  3  miles  northeast  of  Silex.  The  strike  of  the  rocks  is  N.  15°W. 
and  the  dip  65°W.,  Lincoln  County,  Missouri. 


B.     Lower  Warsaw  geode  bed  near  Warsaw,  Hancock  County,  Illinois. 


Illinois  State  Geological  Survey. 


Bulletin  No.  45,  Plate  XL 


A. 


Possible  contact  between  Ste.  Genevieve  and  underlying  St.  Louis  limestone  in  an  old 
quarry  northeast  of  Spanish  Lake,  Missouri. 


B.      Tilted  St.   Louis 


imestone  on  the  south  limb  of  Lii 
Grafton,  Jersey  County,  Illinois 


>ln  fold.  6  miles  viresl   of 


STRATIGRAPHY  41 

Section  immediately  below  the  St.  Louis  limestone  at  Warsaw,  Illinois 

Thickness 
Feet 

Dolomite,  dense,  earthy  with  scattered  quartz  grains 1-2 

Limestone,  gray,  granular,  distinctly  cross-bedded 2-3 

Shale  and  limestone,  earthy,  magnesian 2-3 

Shale  with  lenses  of  blue-gray  more  coarsely  granular  fossiliferous 

limestone 

Shale,  calcareous  with  numerous  geodes  in  lower  portion 35 

Below  the  St.  Louis,  in  the  ravine  east  of  the  north-south 
road  in  the  southeast  corner  of  the  SW.  \i,  sec.  34,  T.  4  N.,  R. 
9  W.,  48  feet  of  lenticular,  earthy,  magnesian  limestone  grading 
to  shale  may  be  found.  None  of  the  granular  limestone  lenses 
found  farther  north  are  present  in  the  60  feet  exposed  here. 
Such  partial  sections  of  this  horizon  as  are  exposed  along  the 
creeks  of  Adams  and  northern  Pike  counties  show  rocks  similar 
to  those  already  described,  with  the  exception  that  the  earthy, 
magnesian  limestones  and  shales  predominate.  Farther  south 
in  Jersey  County,  the  upper  portion  contains  larger  amounts  of 
granular  limestone  and  only  the  lower  30  to  40  feet  are  shale. 
Locally,  oolitic  layers  are  interbedded  with  the  granular  lime- 
stone. 

In  Missouri,  where  this  horizon  is  well  exposed  in  the  vicinity 
of  the  bluffs  in  Clark  and  Lewis  counties,  it  shows  characteristics 
similar  to  those  on  the  Illinois  side.  A  good  exposure  of  the 
horizon  is  to  be  seen  along  the  ravine  just  north  of  St.  Francis- 
ville  in  sec.  32,  T.  65  N.,  R.  6  W.  Other  good  exposures  are  to 
be  seen  along  the  bluff  northward  to  Canton  in  Lewis  County. 
In  St.  Charles  County,  the  Warsaw-Spergen  is  well  exposed  in 
the  bluff  of  Missouri  River  north  of  Greens  Bottom,  sec.  28, 
T.  46  N.,  R.  4  E.,  but  here  the  upper  beds  are  more  calcareous 
and  shale  predominates  only  in  the  lower  40  feet. 

The  thickness  of  this  group  increases  from  north  to  south. 
In  the  northern  portion  as  in  Hancock  County,  Illinois,  and 
Clark  County,  Missouri,  the  thickness  is  between  60  and  80  feet, 
while  in  St.  Charles  County,  Missouri,  it  is  between  125  and  150 
feet,  and  attains  a  similar  thickness  where  exposed  in  Jersey 
County. 

St.  Louis  and  Ste.  Genevieve  formations. — Unlike  the  pre- 
ceding group  the  St.  Louis  and  Ste.  Genevieve  are  mainly  lime- 
stones (PL  XI,  A)  and  contain  practically  no  shale,  except  thin 
partings. 


42  MISSISSIPPI  VALLEY  AREA 

The  distribution  of  these  formations  is  practically  the  same 
as  that  of  the  Warsaw-Spergen,  and  at  most  exposures  St.  Louis 
limestone  is  found  capping  the  lower  formation. 

In  the  more  northern  localities  as  in  Adams  and  Hancock 
counties,  Illinois,  and  Lewis  and  Clark  counties,  Missouri,  the 
basal  portion  of  the  St.  Louis  is  a  brecciated  or  conglomeratic 
limestone  from  10  to  30  feet  in  thickness.  Throughout  this 
region  the  base  of  the  formation  consists  of  a  more  or  less  nodular 
layer  2  to  3  feet  thick,  of  dense,  hard,  very  finely  crystalline 
limestone,  characterized  by  small  crenulations  which  are  made 
prominent  by  thin  lines  of  a  darker  substance  at  intervals  of 
about  Y±  of  an  inch.  Immediately  above  this  basal  layer,  the 
formation  consists  of  boulders  of  limestone  in  a  matrix  of  shale 
which  is  locally  sandy  and  farther  south  becomes  limestone. 
The  limestone  boulders  are  usually  light  gray,  dense,  similar  in 
character  to  the  overlying  layers  but  different  from  the  under- 
lying formations.  The  boulders  vary  in  size  from  less  than  3 
inches  to  several  feet  in  diameter.  This  horizon  becomes  less 
conspicuous  to  the  south  and  at  the  southernmost  exposures  of  the 
St.  Louis  in  St.  Charles  and  Lincoln  counties,  Missouri,  and  Jersey 
and  Madison  counties,  Illinois,  it  is  not  evident  near  the  base  of 
the  formation.  Above  the  brecciated  or  conglomeratic  beds, 
the  limestone  is  commonly  a  light  gray,  hard,  dense  limestone, 
almost  lithographic  in  texture,  and  characterized  by  conchoidal 
fracture.  Generally  it  occurs  in  layers  of  from  a  few  inches  to 
two  feet  thick,  which  are  separated  in  places  by  partings  of  light 
green,  calcareous  shale.  Locally,  layers  of  brown  dolomite  and 
even  sand  lenses  are  found  not  far  above  the  brecciated  portion. 
Chert  layers  and  nodules  are  common.  In  Lewis  and  Clark 
counties,  Missouri,  where  this  formation  may  be  from  40  to  60 
feet  thick,  the  upper  portion  contains  oolitic  layers  interbedded 
with  the  dense,  and  at  several  localities  a  sandstone  layer  up  to 
6  feet  thick  is  present. 

At  the  more  southern  localities,  as  in  the  vicinity  of  Alton 
and  the  southern  tip  of  Calhoun  County  in  Illinois,  and  eastern 
St.  Charles  and  southern  Lincoln  counties,  Missouri,  the  St. 
Louis  limestone  is  much  thicker,  but  the  light  gray  color  and 
the  dense  texture  are  also  characteristic  here.  Oolitic  beds  are 
rare,  although  not  unknown  in  this  formation,  and  do  not  be- 
come prominent  below  the  Ste.  Genevieve.  The  lower  portion 
of  the  St.  Louis  contains  more  or  less  magnesian  limestone. 


STRATIGRAPHY  43 

The  crenulated  layer  so  characteristic  of  the  base  of  the  St. 
Louis  in  the  northern  part,  is  not  evident  in  the  southern  part, 
nor  is  the  brecciated  horizon  developed  near  the  base.  However, 
near  Alton  and  in  the  bluffs  of  southern  Calhoun  County,  Il- 
linois, and  in  southern  Lincoln  County,  Missouri,  a  well  defined 
brecciated  zone  made  up  of  limestone  boulders  of  different  kinds 
of  St.  Louis  limestone  cemented  together  by  limestone  occurs 
about  120  feet  above  the  base  of  the  St.  Louis,  and  curiously 
enough  the  layer  of  limestone  below  it  shows  the  crenulated 
character  so  typical  of  the  basal  St.  Louis  farther  north.  The 
topmost  beds  exposed  in  the  bluff  near  the  town  of  Alton  are  re- 
ferred to  the  Ste.  Genevieve  limestone.  These  upper  beds 
include  at  their  base  a  massive  layer  15  to  20  feet  thick  of  oolitic 
limestone,  overlain  by  about  18  feet  of  massive  sandstone,  above 
which  is  more  oolitic  and  lithographic  limestone.  The  oolitic 
limestone  of  Lewis,  Clark  and  St.  Louis  counties,  Missouri, 
should  also  be  referred  to  the  Ste.  Genevieve,  but  until  more 
detailed  work  is  done  in  this  area  the  exact  relations  of  the  St. 
Louis  and  Ste.  Genevieve  in  this  area  will  remain  in  doubt. 

The  thickness  of  the  St.  Louis  and  Ste.  Genevieve  is  very 
variable.  In  the  more  northern  localities  this  horizon  is  overlain 
by  the  Pennsylvanian  and  was  deeply  eroded  before  the  deposi- 
tion of  that  period.  As  a  result,  there  are  great  differences  in 
thickness  within  short  distances;  locally  all  the  St.  Louis  has 
been  removed  and  the  Pennsylvanian  rests  on  older  formations. 
In  general,  however,  the  thickness  in  Clark  and  Lewis  counties, 
Missouri,  and  Hancock  and  Adams  counties,  Illinois,  ranges 
between  almost  nothing  and  60  feet.  To  the  south  there  is  a 
gradual  thickening  of  this  formation  and  in  the  vicinity  of  Alton, 
it  reaches  a  thickness  between  250  and  270  feet,  of  which  200 
to  225  feet  are  St.  Louis'. 

Pennsylvanian  System 

Rocks  of  the  Pennsylvanian  system  are  present  locally  within 
the  area,  but  are  not  distributed  widely  enough  to  be  of  service 
in  determining  the  structure., 

As  observed,  they  consist  mainly  of  shales  and  sandstone 
with  minor  amounts  of  limestone.  They  occur  as  scattered 
outliers  in  eastern  St.  Charles,  southern  Lincoln,  northern  and 
western  Marion  counties,  and  probably  are  present  beneath  the 
drift  over  most  of  Lewis  and  Clark  counties.     In  Illinois  they 


44  MISSISSIPPI  VALLEY  AREA 

were  observed  only  in  the  eastern  part  of  Hancock  County,  cen- 
tral and  eastern  Adams  County,  northern  Pike  County  and  the 
southern  end  of  Calhoun  County. 

Tertiary  System 

In  southern  Calhoun  County,  one  or  two  of  the  ravines 
revealed  bronzed  and  polished  chert  pebbles,  typical  of  gravels 
in  southern  Illinois  and  Missouri,  considered  as  Tertiary  in 
age,  and  it  is  probable  that  small  patches  of  such  deposits  exist 
beneath  the  overlying  soil  and  drift  at  other  localities  within 
this  area. 

Quaternary  System 

Deposits  of  gravel,  till  and  loess  cover  most  of  the  upland 
back  from  the  bluffs  in  much  of  the  northern  area,  so  that  rock 
outcrops  are  limited  to  the  vicinity  of  the  bluffs  and  the  larger 
streams.  In  the  more  southern  area  of  Calhoun  County,  Illinois, 
and  St.  Charles,  Lincoln,  Pike,  Ralls  and  Marion  counties,  Mis- 
souri, however,  the  drift  is  thin  or  wanting,  and  outcrops  are 
abundant. 


CHAPTER  III— STRUCTURE 
General  Statement 

The  structure  shown  on  the  structure  map  (PL  I)  is  based 
on  the  elevation  of  the  base  of  the  Burlington  limestone.  This 
contact  was  chosen  because  it  was  observed  at  the  greatest 
number  of  places;  is  easily  recognized  in  well  logs;  is  essentially 
parallel  to  the  underlying  formations  in  small  areas;  and  the 
intervals  separating  it  from  other  formations  in  the  geologic 
column  above  the  St.  Peter  sandstone  are  fairly  well  known. 

A  fifty-foot  contour  interval  is  used  in  representing  the  struc- 
ture, as  it  is  felt  that  this  is  the  smallest  interval  that  could  be 
chosen  and  still  be  consistent  with  the  methods  used  and  amount 
of  data  available. 

Most  of  the  elevations  upon  which  the  structure  is  based 
are  given  in  Table  1,  page  8.  Since  the  scarcity  or  abundance 
of  outcrops  has  a  direct  bearing  on  the  accuracy  of  the  detailed 
structural  work,  the  plotted  outcrops  suggest  the  areas  in  which 
such  work  is  feasible  and  also  shows  regions  in  which  structural 
details  will  have  to  be  obtained  from  subsurface  data. 

It  should  be  remembered  in  using  the  map,  that  the  correct- 
ness of  any  contour  is  dependent  upon  the  number  of  observa- 
tions upon  which  it  is  based.  Therefore,  in  areas  where  outcrops 
shown  are  few  or  entirely  lacking,  the  structure  represents  the 
writer's  opinion  only.  The  structural  mapping  of  such  areas  is 
subject  to  change  as  more  data  become  available.  It  is  advisable 
in  all  cases  that  detailed  structural  work  be  done  before  any 
drilling  is  undertaken. 

Structural  Features 

The  most  pronounced  structural  feature  of  the  region  is  a 
large  anticlinal  fold  which  extends  from  Grafton  in  Jersey 
County,  Illinois,  westward  across  southern  Calhoun  County, 
thence  across  the  Mississippi  Valley,  and  continues  westward 
and  southwestward  across  Lincoln,  Pike,  Ralls,  and  southern 
Marion  counties,  Missouri. 

For  convenient  reference,  this  fold  will  be  known  as  the 
Lincoln  anticline,  because  it  reaches  its  greatest  development  in 
Lincoln  County,  Missouri. 

(45)  » 


46  MISSISSIPPI  VALLEY  AREA 

Associated  with  this  fold  is  a  large  fault  designated  by  older 
writers  of  geology  as  the  Cap-au-Gres  fault.  This  fault  parallels 
the  Lincoln  fold  and  breaks  it  just  south  of  the  crest.  In  south- 
western Jersey  and  southern  Calhoun  counties,  Illinois,  and  in 
Lincoln  County,  Missouri,  the  fold  is  most  pronounced  and  ap- 
parently dies  out  both  to  the  east  and  west. 

The  next  fold  of  regional  importance  is  the  anticline  referred 
to  as  the  Pittsfield-Hadley  anticline  in  the  Illinois  State  Survey 
reports16.  This  fold  attains  its  greatest  prominence  near  Pitts- 
field  in  Pike  County,  Illinois,  but  can  be  traced  from  Bedford, 
Illinois,  to  LaGrange,  Missouri.  In  the  vicinity  of  Quincy,  it 
flattens  out  into  a  broad,  flat,  terrace-like  structure,  which  is 
probably  caused  by  the  convergence  of  three  distinct  anticlinal 
areas.  The  general  trend  of  this  terrace,  which  is  a  prominent 
structural  feature  throughout  western  Adams  County,  Illinois, 
is  about  north  and  south. 

The  remaining  area,  which  is  practically  flat,  shows  some 
structural  features,  but  these  are  more  or  less  local.  South 
of  the  Cap-au-Gres  fault  a  pronounced  syncline,  the  axis  of 
which  has  an  east-west  direction,  extends  from  the  vicinity  of 
Troy,  Missouri,  to  Brussels,  Illinois. 

LINCOLN  FOLD 

The  Lincoln  fold  is  not  a  simple  symmetrical  fold,  but  is 
rather  an  area  of  uplift  on  which  are  many  minor  structural 
features  such  as  anticlines,  domes,  synclines  and  faults. 

Direct  evidence  of  the  Lincoln  fold  and  associated  fault  is 
first  seen  in  Illinois  about  one  mile  east  of  Grafton  in  the  ravine 
in  the  NW.  J£  of  sec.  14,  T.  6  N.,  R.  12  W.,  where  the  powder 
plant  is  located.  The  bluff  east  of  the  ravine  is  capped  by  Bur- 
lington limestone,  while  west  of  the  ravine  Silurian  limestone 
makes  up  the  bluff.  In  the  ravine  itself  the  rocks  are  tilted  and 
strongly  suggest  faulting,  though  the  displacement  here  is  not 
very  great,  certainly  less  than  fifty  feet. 

In  the  town  of  Grafton  west  of  the  road  leading  north  in  the 
NW.  \i  of  sec.  15,  T.  6  N.,  R.  12  W.,  the  Silurian  limestone 
along  the  bluff  dips  locally  3  to  4  degrees  south,  showing  the  pres- 
ence of  an  anticline  parallel  to  the  bluff.  The  westward  rise  of 
the  rocks  indicate  it  to  be  an  eastward  pitching  structure. 


"Coryell.  H.  N.,  Parts  of  Pike  and  Adams   counties:     111.  State  Geol.  Survey  Bull.  40, 
p.  75,  1919. 


Illinois  State  Geological  Survey. 


Bulletin  No.  45,  Plate  XII. 


Oolitic  limestone 


'i'i'iV 

Limeslone 


Dolomite 


Shale 


Cross  sections  to  show  the  relation  of  the  Cap-au-gres  fault  to  the   Lincoln  fold. 

A.  Along  Illinois  River  bluff,  Jersey  County,  Illinois. 

B.  Along  Illinois  River  bluff,  Calhoun  County,  Illinois. 

C.  Along  Mississippi  River  bluff,  Calhoun  County,  Illinois. 

D.  Along  Mississippi  River  bluff,  Lincoln  County,  Missouri. 


STRUCTURE  47 

Farther  west  along  the  bluff  road,  in  sees.  13  and  14,  expo- 
sures of  St.  Louis  limestone  and  Pennsylvanian  shale  are  seen 
dipping  steeply  to  the  south  (PL  XI,  B),  and  still  farther  west 
the  cross  section  of  the  fold  as  seen  along  the  north-south  road 
in  sec.  9,  T.  6  N.,  R.  13  W.,  shows  an  unbroken  arch  having  a 
gentle  slope  of  about  twenty-five  feet  per  mile  to  the  north  and 
a  steep  dip  of  almost  forty-five  degrees  to  the  south.  The  lowest 
formation  exposed  is  the  Kimmswick  limestone. 

Across  Illinois  River,  the  fold  again  appears  in  the  bluffs 
in  sec.  35,  T.  12  S.,  R.  2  W.  Although  the  south  limb  still  re- 
tains its  steep  dip,  the  north  limb  is  undulating  with  a  dip  of 
about  25  feet  per  mile,  and  the  crest  of  the  fold,  located  about 
three  miles  north  of  where  the  sharp  change  in  direction  of*  dip 
occurs  (PL  XII,  A),  is  approximately  sixty  feet  higher  than  near 
the  bend,  but  is  about  fifty  feet  lower  than  in  Jersey  County. 
As  no  continuous  section  showing  the  change  from  the  steeply 
dipping  south  limb  to  the  gently  undulating  north  limb  can  be 
seen  here,  it  is  possible  that  there  is  a  break  or  slight  fault  in  the 
fold. 

The  crest  of  the  fold  rises  sharply  to  the  west  and  in  the 
Mississippi  bluffs  in  sec.  29,  T.  12  S.,  R.  2  W.,  if  the  original 
structure  were  restored  would  be  about  350  feet  higher  than  on 
the  Illinois  side  of  Calhoun  County  (PL  XII,  B).  The  forma- 
tions of  the  south  limb  are  almost  vertical,  and  even  the  north 
limb  has  a  pronounced  dip.  Furthermore,  the  abrupt  change  in 
dip  on  the  south  limb  is  marked  by  actual  displacement  which 
causes  Maquoketa  shale  to  abut  against  St.  Peter  sandstone, 
making  a  throw  of  about  300  feet  (PL  XII,  C). 

In  Missouri,  exposures  in  the  river  bluff  about  a  mile  north 
of  Winfield  show  the  crest  of  the  fold  to  have  been  about  100 
feet  higher  than  in  Calhoun  County.  The  south  limb  is  faulted 
and  the  formations  immediately  adjoining  the  fault  are  prac- 
tically vertical.  The  displacement  of  the  fault  is  still  about  300 
feet,  but  the  formations  brought  into  contact  are  the  Jefferson 
City  dolomite  and  the  Plattin  limestone  (PL  XII,  D).  The 
north  limb  of  the  fold  retains  its  more  gentle  dip. 

The  bluff  section  north  of  Winfield  apparently  marks  the 
approximate  top  of  a  dome,  for  westward  the  crest  of  the  anti- 
cline becomes  lower  and  in  the  southeast  corner  of  T.  50  N.,  R. 
1  E.  is  about  200  feet  lower  than  in  the  bluff.  West  from  here 
it  rises  again,  and  in  the  northwest  corner  of  T.  50  N.,  R.  1  E., 
reaches  about  the  same  elevation  as  near  the  bluff.     The  trend 


48  MISSISSIPPI  VALLEY  AREA 

of  the  fold  which  up  to  this  point  has  been  about  N.  70°  W. 
changes  somewhat  abruptly  and  becomes  almost  due  north, 
veering  only  slightly  to  the  west.  This  sharp  northward  bend 
of  the  fold  is  apparently  accompanied  by  faulting,  for  highly 
disturbed  beds  were  observed  in  sec.  3,  T.  50  N.,  R.  1  W.,  and 
also  along  the  road  just  north  of  sec.  3  in  the  adjoining  township. 
The  strike  of  the  rock  in  the  former  case  is  N.  20°  W.  and  the 
dip  55  degrees  west,  while  in  the  latter  case  the  strike  is  about 
north  and  south  and  strata  almost  vertical. 

The  northward  trend  of  the  axis  is  of  short  extent,  for  in  the 
northwest  portion  of  T.  51  N.,  R.  1  W.,  the  axis  turns  westward 
again  and  crosses  the  northern  part  of  T.  51  N.,  R.  2  W.,  in  a 
general  east-west  direction,  and  shows  a  gentle  plunge  to  the 
west.  Near  the  west  line  of  the  township  it  changes  direction 
again  to  northward,  crossing  Pike  County  in  a  N.  20°  W.  direc- 
tion, and  continuing  into  Ralls  County  almost  to  New  London 
where  it  again  turns  to  the  west  and  passes  into  and  crosses 
Marion  County  in  a  N.  50°  W.  direction. 

The  faulting  which  is  so  intimately  associated  with  the 
folding  throughout  most  of  Lincoln  County,  Missouri,  and  Cal- 
houn County,  Illinois,  is  not  prominent  west  of  the  northward 
bend  of  the  fold,  the  only  evidence  of  faulting  west  of  here  being 
the  faulted  zone  along  the  creek  in  sec.  4,  T.  51  N.,  R.  3  W.  For 
a  distance  of  several  hundred  yards  to  the  east  of  the  road,  the 
rocks  are  greatly  fractured  and  minor  faults  extend  in  every 
direction.  It  is  possible,  however,  that  this  faulted  zone  repre- 
sents a  continuation  of  the  main  fault,  though  the  total  dis- 
placement along  the  faulted  zone  does  not  appear  to  be  more  than 
fifty  feet. 

Just  south  of  New  London,  the  trend  of  the  fold  becomes 
more  westerly  again — N.  70°  W.,  and  retains  this  direction  as  far 
west  as  Spaulding  near  the  southeast  corner  of  T.  56  N.,  R.  6  W. 
Throughout  this  extent  the  south  limb  is  steeply  folded,  but  the 
north  limb  dips  gradually.  In  the  vicinity  of  Spaulding,  beds 
have  been  observed  dipping  so  steeply  as  to  suggest  local  fault- 
ing. Beyond  Spaulding,  the  rocks  take  on  a  more  northerly 
trend  once  more,  and  the  fold  crosses  Marion  County  in  an  ap- 
proximate N.  45°  W.  direction  with  the  folding  less  and  less  pro- 
nounced. 


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STRUCTURE  49 


THE  PITTSFIELD-HADLEY  ANTICLINE 

The  Pittsfield-Hadley  anticline,  which  is  roughly  parallel 
to  the  Lincoln  fold,  lies  well  down  the  north  slope  of  that  struc- 
ture. Its  easternmost  expression  in  the  area  under  discussion 
is  found  in  the  Illinois  River  bluff  near  Bedford  in  T.  6  S.,  R.  2 
W.,  where  the  base  of  the  Burlington  limestone  at  the  crest 
of  the  fold  is  about  150  feet  higher  than  the  same  horizon  at  the 
foot  of  the  south  limb.  From  this  point,  the  fold  has  a  general 
northwest  trend,  crossing  Pike  and  southeastern  Adams  counties, 
Illinois,  entering  Missouri  near  the  town  of  LaGrange  in  T.  61 
N.,  R.  6  W.,  and  continuing  across  Lewis  County.  The  crest 
of  the  fold  rises  gradually  west  of  Bedford  to  the  top  of  the 
elongated  dome  located  near  the  center  of  T.  5  S.,  R.  4  W.,  Pike 
County,  where  it  begins  to  descend,  continuing  with  possible 
minor  interruptions  throughout  its  extent.  The  amount  of 
closure  represented  in  the  dome  is  about  175  feet. 

WESTERN  ADAMS  COUNTY  TERRACE 

Near  the  center  of  T.  3  S.,  R.  7  W.,  Adams  County,  the 
Pittsfield-Hadley  anticline,  which  crosses  Pike  County  as  a 
simple  fold,  broadens  out  and  diverges  into  three  distinct  axes. 
One  axis  retains  the  original  trend  and  crosses  over  into  Missouri 
near  LaGrange,  as  mentioned  before.  A  second  one  trends  a 
little  west  of  north  to  near  the  center  of  T.  2  N.,  R.  9  W.,  where 
it  changes  to  a  northwesterly  direction,  entering  Missouri  about 
half  way  between  Gregory  and  Canton  and  continuing  across 
northeastern  Lewis  County  and  southwestern  Clark  County. 
The  third  axis  strikes  northward  through  the  tier  of  townships 
included  in  R.  7  W.  as  far  as  T.  2  N.,  where  it  takes  on  a  more 
easterly  direction  and  apparently  dies  out.  East  of  this  axis, 
the  rocks  dip  gradually  to  the  east,  and  west  of  the  LaGrange 
axis  the  rocks  dip  to  the  west,  but  in  the  intervening  area  the 
strata  are  practically  flat  although  they,  dip  gradually  to  the 
north. 

THE  SOUTHERN  LINCOLN  COUNTY  SYNCLINE 

South  of  the  Cap-au-Gres  fault  the  rocks  are  folded  in  a 
large  eastward  plunging  syncline,  the  axis  of  which  extends 
from  immediately  north  of  Brussels  in  southern  Calhoun  County 
west   across   southern   Lincoln   County,    Missouri,    beyond     the 

4 


50  MISSISSIPPI  VALLEY  AREA 

town  of  Troy  in  T.  49  N.,  R.  1  W.  The  south  limb  of  the  syn- 
cline  strikes  almost  due  west  in  western  Lincoln  County,  but  in 
St.  Charles  County  it  is  northwest-southeast. 

MINOR  STRUCTURES 

Within  the  area  included  by  Hancock  County,  Illinois,  and 
Lewis  County,  Missouri,  the  rocks  are  comparatively  flat  lying 
and  do  not  present  variations  of  over  100  feet.  Such  irregulari- 
ties as  do  occur  are  more  or  less  local,  but  a  few  structurally 
high  areas  appear  to  have  regional  significance. 

In  Lewis  County,  Missouri,  the  rocks  are  arranged  in  a 
series  of  low,  broad  folds  having  a  distinct  northwest-southeast 
trend  and  as  seen  in  the  river  bluffs,  the  northern  third  represents 
the  south  limb  of  an  anticline  whose  crest  is  north  of  the  State 
line.  The  middle  third  shows  a  low  arch  and  the  southern  third 
represents  the  south  limb  of  an  anticline  whose  axis  lies  south 
of  the  County  line. 

A  reflection  of  the  broad  central  fold  is  seen  in  Hancock 
County,  Illinois,  in  the  structurally  high  area  which  extends 
from  north  of  Warsaw  eastward  across  the  county  past  Carthage 
and  leaves  the  county  near  the  junction  of  Tps.  5  and  6  N. 
Other  structurally  high  areas  are  found  near  Nauvoo  in  the 
northwest  corner  of  T.  6  N.,  R.  8  W.,  the  center  of  T.  7  N.,  R. 
8  W.,  and  the  north  half  of  T.  7  N.,  Rs.  5,  6  and  7  W.  A  high 
area  is  also  indicated  in  the  western  part  of  T.  4  N.,  R.  5  W. 
In  addition  to  minor  folds  mentioned,  many  smaller  folds  are 
indicated  in  the  structure  sections  of  the  bluffs  and  a  small  fold 
is  also  shown  in  the  Missouri  River  bluff  west  of  the  center  of 
T.  46  N.,  R.  4  E. 

Periods  of  Deformation 

The  structure  as  represented  on  the  structure  map  is  for 
the  most  part  the  result  of  post-Pennsylvanian  deformation,  but 
inasmuch  as  it  is  based  entirely  on  data  obtained  from  Missis- 
sippian  rocks  it  is  not  improbable  that  it  diverges  somewhat  from 
a  representation  of  only  Pennsylvania  deformation,  and  com- 
bines elements  of  both  post-Pennsylvanian  and  pre-Pennsyl- 
vanian  deformation. 

A  study  of  the  stratigraphy  shows  that  the  rocks  were  ele- 
vated and  submerged  several  times  within  the  geologic  history 
of  the  region,  and  that  the  changes  in  level  were  sometimes  "ac- 


STRUCTURE  51 

companied  by  warping.  Since  no  oil  has  ever  been  found  in 
rocks  older  than  the  Kimmswick  ("Trenton"),  a  consideration 
of  deformation  previous  to  that  time  is  not  pertinent  to  a  discus- 
sion which  deals  with  a  structural  reconnaissance  made  for  the 
purpose  of  considering  the  relation  of  structure  to  the  possibility 
of  finding  oil,  and  will  therefore  not  be  included. 

Times  of  submergence  were  usually  inaugurated  by  a  warp- 
ing and  sinking  of  the  areas  adjoining  the  Ozark  region,  while 
the  Ozarks  themselves  apparently  remained  stationary  or  sank 
more  slowly.  Upon  emergence  the  Ozark  region  was  generally 
the  first  to  become  land,  and  since  the  Ozark  region  was  land 
during  most  of  Paleozoic  times  the  formations  laid  down  during 
that  time  thin  out  towards  the  Ozarks  and  often  change  in  char- 
acter as  the  old  land  masses  are  approached. 

The  retreat  of  the  sea  after  the  Kimmswick  limestone  had 
been  lain  down  was  accompanied  by  a  slight  tilting  of  the  strata 
to  the  southeast,  and  possibly  a  slight  downwarp  of  the  beds  just 
north  of  the  area  included  in  this  report.  Subsequent  erosion, 
therefore,  left  deposits  which  thicken  to  the  south  and  east,  the 
rate  of  increase  averaging  not  much  over  two  feet  per  mile,  al- 
though there  is  local  variation. 

During  the  next  submergence  or  possibly  during  the  emer- 
gence after  the  Maquoketa  shale  had  been  deposited,  the  surface 
was  again  tilted,  but  this  time  to  the  north,  for  that  formation 
thickens  to  the  north  and  east.  The  amount  of  tilting  was  again 
small  in  the  northern  portion  of  the  area,  but  becomes  increas- 
ingly greater  to  the  east  where  the  dip  may  reach  as  much  as  20 
feet  or  more  per  mile. 

During  the  ensuing  Silurian  period,  and  possibly  immedi- 
ately after,  there  may  have  been  a  slight  sagging  in  the  southern 
portion  of  the  area,  as  evidenced  by  the  presence  of  Silurian 
strata  in  Jersey  and  Calhoun  counties,  Illinois,  and  in  northern 
Lincoln,  Pike,  and  southern  Ralls  counties,  Missouri,  and  the 
absence  of  these  formations  in  the  north  central  part  of  the  area. 
They  are  also  known  to  be  present  in  the  eastern  portion  of  the 
area,  although  in  diminished  thickness,  but  their  very  presence 
there  suggests  continued  slight  tilting  to  the  east. 

The  presence  of  the  Silurian  in  the  southern  portion  of  the 
area  may  also  be  accounted  for  by  considering  that  the  area 
was  lowered  more  than  the  rest  by  erosion  and  by  subsidence 
subsequently  became  occupied  by  an  arm  of  the  Silurian  sea. 


52  MISSISSIPPI  VALLEY  AREA 

North  of  the  area  under  consideration  there  is  known  to  have 
been  pronounced  sagging  during  Silurian  times. 

Though  the  Devonian  in  Illinois  and  eastern  Missouri  was 
marked  first  by  depression  to  the  southeast,  south  of  the  region 
studied,  and  later  by  depression  to  the  north  of  the  area  studied, 
the  amount  of  folding  or  warping  which  actually  took  place 
within  this  area  is  apparently  negligible,  and  although  a  thick- 
ness of  125  feet  and  more  of  northern  Devonian  rocks  does  oc^ 
cur  in  Ralls  County,  their  relations  are  such  as  to  suggest  that 
they  are  deposits  formed  in  bays  occupying  pre-Devonian 
erosional  lowlands. 

If  the  black  shale  above  the  Devonian  limestones  is  con- 
sidered Mississippian  in  age,  then  the  Mississippian  was  inau- 
gurated in  this  area  by  a  tilting  to  the  northeast.  As  in  earlier 
periods  the  amount  of  tilting  is  appreciable  only  if  widely  sepa- 
rated areas  be  considered,  as  its  average  is  less  than  5  feet  per 
mile,  though  it  varies  locally. 

In  the  transition  from  Mississippian  to  Pennsylvanian 
times  there  was  warping  as  is  shown  by  the  fact  that  apparently 
flat  lying  Pennsylvanian  rocks  rest  at  the  same  elevation  on 
rocks  as  low  as  the  Burlington,  or  as  high  as  the  St.  Louis  strati- 
graphically.  The  amount  of  warping  or  tilting  is  slight  and  ap- 
pears to  correspond  roughly  with  existing  structures. 

Besides  the  main  epochs  of  warping  mentioned  there  have 
been  many  others  whose  records  are  not  readily  discernible,  and 
it  is  impossible  with  the  data  at  hand  to  attempt  to  outline  even 
the  larger  features.  The  resulting  effect  of  these  different  periods 
of  warping  has  been  to  destroy  the  parallelism  of  the  formations 
of  different  periods,  or  even  formations  of  the  same  period. 
Apparently,  however,  the  last  period  of  warping  was  the  greatest, 
and  since  all  deformation  of  surface  rocks  is  reflected  to  some 
depth  in  the  underlying  strata,  structures  corresponding  to  the 
surface  rock  structure  are  also  found  in  the  underlying  beds. 
It  is  possible,  however,  that  the  outlines  of  low,  broad  folds  found 
at  the  surface  may  be  completely  neutralized  in  the  lower  strata 
by  underlying  structures  formed  at  some  earlier  period,  and  it  is 
just  as  possible  that  folds  which  are  present  in  lower  rocks  do 
not  have  any  surface  expression  and  can  be  discovered  only 
from  study  of  subsurface  data.  Difference  in  trend  of  early 
folds  crossed  by  later  folds  tends  to  alter  outlines  of  the  struc- 
ture, but  in  this  area  later  folds  appear  to  parallel  and  accentuate 
earlier  ones. 


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STRUCTURE  53 

In  this  region,  the  major  effect  has  been  to  cause  a  gradual 
divergence  of  the  strata  toward  the  center  of  the  Illinois  basin 
to  the  east.  Plates  XIII  and  XIV  illustrate  the  changes  from 
north  to  south  on  the  Missouri  and  Illinois  sides  of  the  Mississippi 
Valley  area.  Plate  XV  represents  a  generalized  section  from 
Clark  County,  Missouri,  to  Hancock  County,  Illinois;  Plate  XVI 
represents  one  farther  south  across  Marion  County,  Missouri, 
and  Adams  County,  Illinois,  and  Plate  XVII  one  across  Pike 
County,  Missouri,  Calhoun  and  Western  Greene  counties, 
Illinois.  Many  other  local  and  minor  variations  also  occur,  but 
these  can  be  determined  only  from  a  detailed  study  of  the  area. 


CHAPTER  IV— OIL  POSSIBILITIES 

Introduction 

Except  for  the  small  amounts  of  gas  obtained  from  the 
Pittsfield-Hadley  dome  in  Pike  County,  Illinois,  there  is  no  pro- 
duction of  oil  or  gas  within  the  area  described  in  this  report. 
The  nearest  producing  field  is  the  Colmar  field,  located  near  the 
eastern  edge  of  Hancock  County,  Illinois,  in  T.  4  N.,  R.  4  W., 
in  which  the  oil  is  obtained  from  discontinuous  sand  lenses  at 
the  top  of  the  Maquoketa  shale.  South  of  the  area  there  is  oil 
production  from  the  Kimmswick  ("Trenton")  in  the  vicinity 
of  Waterloo,  Monroe  County,  Illinois,  and  to  the  east  some  oil 
is  obtained  from  the  top  of  the  Mississippian  rocks  near  Jackson- 
ville, and  from  Pennsylvanian  rocks  near  Carlinville  and  Staun- 
ton, Macoupin  County,  Illinois.  The  adjoining  area  in  Mis- 
souri has  not  produced  oil. 

Previous  Exploration 

Most  of  the  deep  wells  in  the  Missouri  portion  of  the  area, 
of  which  there  is  any  record,  have  been  drilled  for  water,  and  are, 
therefore,  not  oil  tests.  It  is  improbable,  however,  that  any 
good  show  of  oil  would  be  overlooked  even  in  wells  drilled  for 
water,  and  they  may,  in  a  measure,  be  considered  oil  tests. 

Jt  should  be  remembered,  however,  that  water  wells  are 
located  without  regard  to  structure,  so  that  absence  of  oil  in  no 
way  condemns  any  of  the  surrounding  territory  which  is  struc- 
turally more  favorably  located.  A  detailed  discussion  of  the 
relations  of  wells  drilled  to  future  prospecting  is  out  of  place  in 
a  general  discussion  such  as  this,  and  should  be  considered  in 
more  detailed  work. 

In  Illinois,  the  discovery  of  oil  in  the  Colmar  field  just  east 
of  Hancock  County,  and  the  presence  of  gas  in  the  Pittsfield- 
Hadley  dome  have  stimulated  the  search  for  oil  in  areas  within 
this  State,  and  a  correspondingly  greater  number  of  oil  tests 
have  been  drilled.  The  approximate  location  of  these  wells  is 
shown  on  the  accompanying  map  (PL  I),  and  the  available  logs 
are  given  in  the  succeeding  pages. 

All  areas,  within  which  detailed  structural  work  has  been 
done,  are  indicated  on  Plate  I. 

(54) 


OIL  POSSIBILITIES  55 


Review  of  the  Principles  of  Oil  Accumulation 

In  considering  the  oil  possibilities  of  any  area,  many  factors 
must  be  taken  into  account  besides  the  structure,  and  it  is  only 
after  all  known  factors  have  been  considered  that  intelligent 
prospecting  can  be  done.  Therefore,  before  continuing  a  de- 
tailed discussion  of  the  oil  possibilities  and  the  factors  operating 
to  bring  them  about,  a  brief  review  of  generally  accepted  princi- 
ples is  presented. 

In  order  that  commercial  deposits  of  oil  may  be  formed 
the  source  must  be  adequate  and  in  the  productive  regions  of 
this  continent  there  are  usually  heavy  beds  of  carbonaceous 
shale  or  thick  horizons  of  limestone  that  are  highly  fossiliferous. 
The  matter  of  adequate  source  is  the  prime  factor  as  without  it 
accumulation  cannot  take  place  even  though  structural  condi- 
tions may  be  perfect. 

ORIGIN  OF  OIL 

Oil  and  gas  are  apparently  derived  from  vegetable  and  ani- 
mal matter  which  is  buried  with  the  lime,  mud,  or  sands  that 
comprise  the  rocks.  After  the  carbonaceous  matter  is  once 
entombed  in  the  rocks  and  oil  is  formed,  various  forces  tend  to 
move  it  about,  and  under  certain  conditions  concentrate  it  in 
local  areas,  thus  giving  rise  to  so-called  oil  pools. 

MIGRATION  OF  OIL 

The  forces  or  factors  most  active  in  the  migration  of  oil  are: 
(1)  gravity;  (2)  gas  pressure;  (3)  capillarity;  (4)  difference  in 
specific  gravity  of  oil  and  water;  (5)  flow  of  underground  waters, 
and  (6)  pressure  from  sedimentation  and  deformation. 

(1)  Gravity  is  effective  only  in  dry  rocks,  in  which  the 
pore  space  is  large  enough  to  be  overcome  by  the  influence  of 
capillarity.  (2)  Pressure  developed  in  gas  by  any  means  such 
as  heat,  chemical  action,  etc.,  would  tend  to  cause  the  gas  to 
expand,  and  if  the  pressure  became  great  enough,  would  force 
any  oil  in  the  surrounding  pores  to  move  out  ahead  of  it.  (3) 
Capillary  attraction  in  dry  rocks  would  tend  to  draw  the  oil  into 
the  finer  pores,  but  if  water  is  present,  the  greater  attraction  of 
the  water  would  cause  the  water  to  be  drawn  into  the  finer  pores, 
and  tend  to  concentrate  the  oil  in  the  larger  pores.  (4)  The 
difference  in  specific  gravity  of  oil  and  water  in  rocks  which  are 


56  MISSISSIPPI  VALLEY  AREA 

saturated,  or  partly  saturated,  with  a  mixture  of  both,  causes  a 
separation  of  the  two  and  a  movement  of  the  oil  to  the  top  of  the 
water.  In  tilted  rocks,  the  amount  of  movement  due  to  this 
cause  may  be  considerable.  (5)  In  water-bearing  rocks,  the 
water  does  not  commonly  remain  stationary,  and  under  favorable 
circumstances  as  when  rocks  are  tilted  or  folded  and  exposed  at 
two  different  levels,  there  may  be  a  definite  artesian  circulation, 
causing  the  oil  to  be  carried  along  on  top  of  the  water  considerable 
distances  to  be  trapped  by  higher  folds,  or  flushed  out  of  the 
rocks  entirely.  (6)  Probably  the  greatest  force  in  concen- 
trating the  oil  eventually  in  the  more  porous  layers  of  rock  is  the 
increase  in  pressure  on  the  original  oil-bearing  strata  by  deposi- 
tion of  overlying  layers  of  rock  or  the-  diastrophic  force  which 
induces  folding.  The  weight  of  the  superincumbent  layers,  or 
the  pressure  causing  folding  compacts  the  lower  layers,  and  the 
oil  originally  present  in  the  more  shaly  beds  is  forced  out  into  the 
porous  sand  layers  in  which  the  individual  grains  do  not  com- 
pact so  readily. 

ACCUMULATION    OF    OIL 

Conditions  essential  to  the  accumulation  of  oil  into  pools 
are:  (1),  a  porous  stratum  which  can  be  made  to  serve  as  a 
reservoir;  (2),  an  impervious  covering  of  rock  to  retain  the  oil 
in  the  reservoir,  and  (3),  tilting,  folding,  terracing  or  other 
structural  modification  that  will  cause  large  quantities  of  oil  to 
collect  and  be  retained  within  a  comparatively  small  area. 

The  reservoir  is  commonly  supplied  by  sandstone,  but  any 
rock  which  offers  sufficient  voids  is  a  prospective  reservoir. 
Thus  limestones,  which  have  become  dolomitized,  or  fractured,  or 
have  been  exposed  to  weathering,  or  contain  porous,  granular 
and  oolitic  layers  have  all  been  known  to  act  as  reservoirs. 
Even  shales  which  are  usually  too  compact  to  act  as  reservoirs, 
may  provide  a  suitable  reservoir  in  exceptional  cases,  as  when 
fractured  along  a  fault.  The  cap  rock  or  impervious  cover  of 
the  reservoirs  is  generally  a  shale,  but  a  dense  limestone  or  ce- 
mented sandstone  may  serve  equally  as  well. 

The  outlines  of  the  reservoirs  are  in  most  cases  the  result 
of  folding  of  the  rocks.  The  "lie"  of  the  rocks  is  known  as  the 
structure,  the  determination  of  which  is  exceedingly  important 
in  the  discovery  and  development  of  an  oil  field.  The  most 
favored  location  for  a  reservoir  depends  upon  the  amount  of 
water  contained  in  oil-bearing  rocks. 


Illinois  State  Geological  Survey. 


Bulletin  No.  45,  Plate  XVIII. 


Ist.drill  hole 


3rd. drill  hole 

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«=>.      •_!_£>   .^^X            jf 

•       o        •      o   •      • 
o   '       *        •     .     .o 

i^ll&=r^^^ 

gS^^^^^ 

Til  Drift 
;•;•;  Sand 

^^-^uL^T^"7"^^ — '"-r^S^ 

c 

9 

1 

Miles                     2 

3 

— i 

Diagram  showing  conditions  governing  oil  accumulation 

A.  In  oil  sands  saturated  with  water. 

B.  In  oil  sands  partly  saturated. 

C.  In  sands  containing  no  water  and  only  partly  Idled  with  oil. 


OIL    POSSIBILITIES  0? 

In  water-bearing  rocks,  structures  of  the  dome  type,  long 
arches  designated  as  anticlines,  terraces  made  by  flattening  of 
the  dip,  or  monoclines  are  all  known  to  be  sites  of  possible 
reservoirs  (PL  XVIII).  The  reason  for  this  is,  of  course,  that 
after  folding,  the  oil  and  gas  which  was  once  spread  out  thinly 
over  a  wide  area,  in  rising  to  the  top  of  the  water,  becomes  trapped 
in  these  structures  and  therefore  concentrated  within  a  small 
area.  Other  factors  beside  folding,  however,  may  bring  about 
similar  conditions.  Thus,  sand  lenses  completely  surrounded  by 
shale  may,  even  where  the  strata  are  flat  lying,  have  enough  slope 
to  the  upper  surface  to  permit  the  oil  to  gather  at  one  end.  In 
tilted  rocks  where  oil-bearing  strata  are  exposed  at  the  surface, 
the  escaping  oil  may  leave  deposits  of  asphalt  which  effectively 
seal  the  outcrop  and  permit  the  accumulation  of  oil  immediately 
behind  the  outcrop.  Rocks  once  exposed  to  surface  weathering 
and  erosion,  become  iruore  porous  and  later  when  buried,  may 
become  reservoirs.  In  faulted  regions,  the  formation  of  gouge 
may  seal  the  fault  and  permit  accumulation  of  oil  along  the  fault 
zone.  In  short,  any  set  of  circumstances  which  will  cause  a 
concentration  of  oil  or  gas  from  a  larger  area  to  a  smaller  one 
may  produce  oil  or  gas  pools. 

As  gravity  is  the  effective  migratory  force  in  rocks  barren 
of  water,  oil  will  work  down  the  dip  of  the  rocks  and  collect 
at  the  lowest  possible  place,  such  as  bottom  of  synclines  or  sags 
on  the  slopes,  in  positions  the  reverse  of  those  when  the  sands  are 
filled  with  water  (PI.  XVIII,  C).  Dry  sands,  however,  are  not 
common  in  the  area  here  considered. 

COMBINED  EFFECT  OF  FOLDING  AND  EROSION 

After  oil  has  become  concentrated  in  folds  there  is  the  possi- 
bility that  subsequent  erosion  will  expose  the  oil-bearing  strata 
at  the  surface  and  incoming  fresh  waters  may  flush  out  the  oil 
from  reservoirs  near  the  outcrop. 

Evidences  of  Oil  and  Gas  Within  the  Region 

Aside  from  the  fact  that  oil  is  produced  in  adjoining  regions, 
there  is  direct  evidence  that  oil  has  been,  and  may  be,  present 
within  this  region.  The  best  evidence  of  this  is,  of  course,  the 
actual  production  of  gas  from  the  Pittsfield-Hadley  dome. 
Other  evidence,  however,  is  furnished  by  the  presence  of  the 
oil-bearing  shales  of  the  Sweetland  Crepk  formation;  by  the  thin 


58  MISSISSIPPI  VALLEY  AREA 

shaly  partings  at  the  top  of  the  Plattin  limestone,  which  burn 
readily  when  ignited;  and  by  the  presence,  locally  in  both  the 
Kimmswick  limestone  and  Edgewood  dolomite  of  small  pockets 
containing  black  asphaltic  residuum.  Near  Niota,  Hancock 
County,  Illinois,  a  thin,  geodiferous  layer  near  the  top  of  the 
Keokuk  limestone  contains  numerous  geodes  filled  with  heavy, 
black  oil,  but  the  surrounding  rock  is  not  bituminous.  At  several 
localities  within  the  area,  drillers  of  deep  wells  have'  reported 
shows  of  oil  and  gas  in  the  Kimmswick  ("Trenton")  limestone, 
in  the  "Niagaran  dolomite,"  from  sandy  phases  of  the  Kinderhook 
and  Sweetland  Creek  shales,  and  also  from  the  Burlington  lime- 
stone. 

Probable  Oil  Horizons 

The  greatest  production  of  oil  in  Illinois  comes  from  the 
Pennsylvanian  and  upper  Mississippian  formations,  but  some 
oil  has  also  been  produced  from  the  formations  of  the  lower 
Mississippian  system,  the  Devonian,  the  Silurian,  and  the  upper 
formations  of  the  Ordovician  system.  In  fact,  the  producing 
horizons  of  oil  are  so  widely  distributed  that  no  test  can  be  con- 
sidered complete  unless  it  penetrates  the  Kimmswick  ("Tren- 
ton"). Nowhere,  however,  within  the  State  has  oil  been  found 
below  the  Kimmswick. 

Within  the  area  considered,  the  number  of  probable  oil 
horizons  is  less  than  in  the  interior  of  the  State,  for  no  upper 
Mississippian  rocks  are  present;  the  Pennsylvanian  rocks  are 
thin  or  lacking,  and  where  present  they  represent  the  surface 
rock  so  that  any  oil  they  may  have  contained  once  has  long  since 
escaped.  The  Osage  and  Meramec  rocks  also  outcrop  at  the 
surface  over  most  of  the  area,  but  these  horizons  are  negative  so 
far  as  oil  production  is  concerned.  Therefore,  of  the  oil  producing 
horizons,  only  the  Kinderhook,  the  Devonian,  Silurian,  and  upper 
Ordovician  offer  possibilities. 

Factors  Affecting  Oil  Accumulation  Within  the  Area 

structure 

As  shown  in  the  chapter  describing  the  structure,  there  are 
a  number  of  distinct  folds  which  might  have  caused  a  gathering 
and  localization  of  any  oil  present  in  the  rocks.  These,  in  the 
order  of  their  size,  are  the  Lincoln  fold,  the  Pittsfield-Hadley 


OIL   POSSIBILITIES  59 

anticline,  the  Adams  County  terrace,  and  the  minor  structurally 
high  areas  in  Hancock  County,  Illinois,  and  Clark  County, 
Missouri. 

THE    LINCOLN    FOLD 

Though  possessing  many  excellent  minor  structural  irregu- 
larities which  might  have  caused  localization  of  oil,  the  Lincoln 
fold  can  not  be  considered  as  a  possible  oil  structure  because  its 
crest  and  slopes  expose  rocks  lower  than  the  Kimmswick.  Any 
oil  that  may  have  been  present  in  this  structure  has  long  since 
escaped.  For  this  reason,  northeastern  Lincoln  County,  central 
and  eastern  Pike  County,  and  all  except  the  extreme  western 
part  of  Ralls  County  do  not  warrant  prospecting  for  oil.  In 
Marion  County,  where  the  crest  of  the  anticline  plunges  to  the 
northwest,  and  possible  oil-bearing  strata  have  an  impervious 
cover,  the  discovery  of  doming  anywhere  along  the  crest  of  the 
axis  might  be  considered  favorably.  Similarly,  any  minor 
folding  in  western  Ralls  and  Pike  counties  which  interrupt 
the  regional  southwest  dip  might  also  bear  investigation.  These 
possibilities  are  the  only  favorable  structural  features  associated 
with  the  Lincoln  fold,  and  although  reconnaissance  work  did 
not  offer  much  promise,  a  suggestion  of  a  flattening  and  minor 
folding  was  observed  in  the  vicinity  of  Center,  in  western  Ralls 
County. 

PITTSFIELD-HADLEY    ANTICLINE 

The  Pittsfield-Hadley  anticline  shows  a  distinct  doming 
in  Pike  County,  Illinois,  and  since  some  of  the  probable  oil- 
bearing  horizons  are  present  here,  under  sufficient  cover  this 
dome  might  be  considered  favorable.  Southeast  and  northwest  of 
Pike  County,  the  axis  of  the  fold  plunges  gently  away  from  the 
dome,  and  other  localities  which  might  be  considered  structurally 
favorable  can  be  proved  only  by  the  discovery  of  other  doming 
along  the  crest.  No  evidence  pointing  to  such  doming  was 
observed  in  this  reconnaissance,  and  can  be  determined  only  by 
detailed  work. 

ADAMS    COUNTY    TERRACE    OR    MONOCLINE 

The  broad  northward  dipping  monocline  that  underlies 
western  Adams  County  can  be  considered  favorable  structure 
only  if  detailed  work  shows  it  to  possess  minor  folding  which 
might  serve  to  trap  any  oil  migrating  up  the  slope.  However, 
ho  prominent  folding  of  this  kind  was  observed. 


60  MISSISSIPPI  VALLEY  AREA 


MINOR    STRUCTURES 

The  higher  portions  of  the  minor  structures  of  Hancock 
County,  Illinois,  and  Clark  County,  Missouri,  should  be  con- 
sidered possible  oil  structures  only  after  drilling  has  shown 
production  on  the  more  favorable  ones  farther  south. 

EFFECT  OF  EARLIER  PERIODS  OF  FOLDING 

In  discussing  periods  of  earlier  folding,  it  was  shown  that 
throughout  this  area  there  has  been  continuous  tilting  to  the  east, 
and  much  to  the  north.  The  effect  of  such  tilting,  of  course, 
would  be  to  permit  the  oil  to  migrate  up  the  dip  to  the  west  and 
south.  If  then  these  earlier  formations  were  exposed  at  the 
surface  after  being  tilted,  any  oil  they  may  have  contained, 
except  for  small  quantities  as  were  caught  within  minor  irregular 
warps  and' folds,  would  have  escaped.  That  the  lower  rocks, 
especially  the  Kimmswick  ("Trenton")  limestone  were  exposed 
at  the  surface  as  late  as  Devonian  time  is  shown  in  Ralls  County, 
where  the  Devonian  rests  on  Kimmswick,  and  in  St.  Charles 
County,  where  the  Kimmswick  limestone  was  the  surface  rock 
as  late  as  Kinderhook  time.  These  facts  are  unfavorable  to  the 
occurrence  of  oil  in  the  Kimmswick  in  this  region  except  in 
places  where  the  oil  might  have  been  retained  due  to  local  fold- 
ing, which  trapped  the  oil  and  retained  it  during  future  folding. 

CONCLUSION    CONCERNING    STRUCTURAL    FACTORS 

That  the  predominating  anticlinal  fold  of  the  region  should 
expose  all  the  known  oil-bearing  rocks  at  the  surface  is  considered 
unfavorable  to  large  accumulations  of  oil  within  the  region. 
The  oil-bearing  horizons  are  of  necessity  barren  in  the  vicinity  of 
their  outcrop,  but  may  contain  oil  in  some  of  the  minor  folds 
where  they  are  under  sufficient  cover  to  prevent  the  escape  of 
the  oil. 

Structures  most  favorable  to  the  retention  of  oil  are,  there- 
fore, minor  folds  on  the  slopes  of  the  Lincoln  fold,  and  any 
doming  along  the  crest  of  the  fold  where  it  plunges  in  Marion 
County  and  farther  northwest.  The  order  of  importance  of 
these  minor  structures  is:  (1)  small  domes  or  buckling  of  the 
crest  of  the  Lincoln  fold  from  Marion  County,  Missouri,  north- 
westward; (2)  minor  anticlines  or  closures  on  the  slope  of  the 
fold  in  western  Ralls  and  Pike  counties,  Missouri;  (3)  Pittsfield- 
Hadley   dome   and   other   closures   found   along   the   crest;    (4) 


OIL   POSSIBILITIES  61 

closures  on  the  Adams  County  monocline;  and  (5)  closures  in 
the  gently  folded  areas  in  Hancock  County,  Illinois,  and  Clark 
and  Lewis  counties,  Missouri. 

The  earlier  folding  in  the  area,  accompanied  by  exposure  of 
the  rocks,  is  considered  unfavorable  to  the  retention  of  oil  except 
locally,  in  rocks  below  the  Devonian  in  the  western  part  of  the 
area,  but  it  is  not  so  important  in  the  eastern  portion,  which  is 
nearer  to  the  center  of  the  Illinois  basin,  because  folding  here  was 
not  always  accompanied  by  exposure  of  the  strata. 

STRATIGRAPHY 

The  presence  of  bituminous  material  in  all  the  shale  forma- 
tions and  the  fact  that  some  of  the  shales  as  the  Sweetland  Creek, 
will  give  off  oil  on  distillation,  suggest  that  the  shales  are  probably 
the  original  source  for  most  of  the  oil  present  within  the  area. 
Accumulations  of  oil  should  therefore  occur  in  the  associated 
porous  rocks. 

Rocks  that  might  act  as  reservoirs  which  are  associated  with 
shale  formations  are:     (1)  Kimmswick   ("Trenton")  limestone; 

(2)  local  sand  lenses  at  the  base  of  the  Silurian  (Hoing  sand); 

(3)  Silurian  limestone  and  dolomite;  (4)  Devonian  limestones; 
(5)  Louisiana  limestone;  (6)  local  sand  layers  within  the  Sweet- 
land  Creek  shale;  and  (7)  dolomitic  layers  of  the  Chouteau  and 
Burlington  formations. 

KIMMSWICK    ("TRENTON")    LIMESTONE 

Although  the  name  "Trenton"  is  in  common  usage  in  the 
oil  industry  for  formations  of  this  horizon,  the  proper  name  of 
this  formation  in  this  region  is  Kimmswick.  The  limestone  is 
directly  below  the  locally  bituminous  Maquoketa  shale,  and  the 
"Trenton"  itself  shows  oil  shale  partings  at  the  top  of  the  Plattin. 
Another  factor  favoring  accumulation  of  oil  in  the  Kimmswick 
is  its  porosity,  though  it  diminishes  to  the  north  and  east  where 
the  granular  layers  become  subordinate  and  are  interbedded  with 
dense  fine  grained  layers. 

Several  other  unfavorable  circumstances  beside  those  due 
to  structure  and  distribution  already  mentioned  may  be  noted. 
Locally,  as  in  northern  Ralls  County,  Missouri,  the  Maquoketa 
shale  is  absent  above  the  Kimmswick.  It  outcrops  at  higher 
levels  both  to  the  north  and  south  of  the  area  under  discussion, 
so  that  there  may  exist  an  artesian  circulation  which  would  Lend 


62  MISSISSIPPI  VALLEY  AREA 

to  flush  out  any  oil  from  its  path.  A  suggestion  of  such  circula- 
tion is  found  in  the  apparent  decrease  in  the  salinity  of  water  in 
this  horizon  from  its  outcrop  northward.  Fresh  water  was  found 
at  a  depth  of  500  feet  below  the  valley  flat  in  the  Kimmswick  in 
a  well  drilled  at  Warsaw,  Hancock  County,  Illinois,  and  farther 
north  near  Stronghurst,  in  Henderson  County,  Illinois,  both  fresh 
and  salt  water  are  reported  from  the  Kimmswick.  Also,  where 
tested  under  the  most  favorable  structural  conditions  on  the 
Pittsfield-Hadley  anticline  the  Kimmswick  did  not  yield  oil. 

HOING    SAND 

The  Hoing  sand  is  not  known  from  outcrop,  and  is  appa- 
rently limited  in  its  distribution  within  this  area  to  the  eastern 
portion,  in  Hancock  and  Adams  counties,  Illinois.  So  far  as 
known,  the  sand  occurs  as  discontinuous  lenses,  and  though 
ideally  situated  as  regards  its  relations  to  a  shale  body,  it  is  an 
important  probable  oil  horizon  over  only  a  small  area. 

SILURIAN    LIMESTONE    AND    DOLOMITE 

Where  the  Hoing  sand  is  absent,  the  porous  Silurian  dolo- 
mite of  the  Alexandrian  series  is  the  rock  immediately  above  the 
Maquoketa,  and  might  serve  as  an  oil  reservoir.  The  unfavorable 
feature  of  the  Silurian  is  its  limited  distribution,  for  it  is  present 
under  sufficient  cover  only  in  the  eastern  portion  of  the  area,  in 
Hancock,  Adams,  and  Pike  counties,  Illinois. 

DEVONIAN    LIMESTONE 

The  Devonian  limestone  is  thin  and  has  about  the  same  dis- 
tribution as  the  Niagaran.  In  the  southern  portion  of  the  area, 
it  contains  sandy  beds,  both  near  the  top  and  at  the  base,  but 
these  beds  also  are  under  sufficient  cover  only  in  the  eastern 
portion  of  the  region  here  considered. 

SWEETLAND    CREEK    SHALE 

The  Sweetland  Creek  shale  is  locally  sandy  near  its  base,  and 
such  sandy  phases  are  excellent  prospective  oil  reservoirs.  As 
much  as  8  feet  of  sandstone  have  been  observed  in  the  Sweet- 
land  Creek  shale  along  Brush  Creek  in  the  region  where  it  joins 
Spencer  Creek  in  southern  Ralls  County,  and  the  basal  portion 
of  shale  is  also  sandy  in  Pike  County,  Illinois,  where  it  is  exposed 
in  the  bluff  north  of  Pleasant  Hill.  These  sandy  phases,  however, 
appear  to  be  only  local  developments. 


OIL   POSSIBILITIES  63 


LOUISIANA    LIMESTONE 


The  Louisiana  limestone  is  typically  a  dense,  almost  litho- 
graphic rock,  entirely  unsuitable  as  a  retainer  of  oil,  and  although 
it  is  possible  that  it  may  be  locally  fractured  or  contain  porous 
dolomitic  beds,  it  is  probably  not  important  as  a  possible  oil- 
producing  horizon. 

KINDERHOOK    SHALE 

The  Kinderhook  shale  is  locally  sandy  with  medium-sized 
grains  and  might,  under  proper  conditions,  become  a  reservoir 
for  oil.  It  is  exposed  at  the  surface  over  most  of  the  southern 
portion  of  the  area,  and  exists  under  cover  only  in  the  northern 
part. 

HIGHER    FORMATIONS 

None  of  the  higher  formations  is  present  here  under  suffi- 
cient cover  to  warrant  considering  their  oil  possibilities. 

Summary  of  Conclusions 

The  conclusions  drawn  from  a  study  of  the  data  afforded  by 
this  reconnaissance  are: 

(1)  That  the  region  does  not  offer  much  promise  of  more  than 
small  local  production. 

(2)  That  the  Kimmswick  ("Trenton")  limestone,  which  is 
in  general  the  most  promising  oil  horizon  in  western  and  south- 
western Illinois,  is  distinctly  less  favorable  to  possible  production 
in  this  region  than  it  is  farther  south  and  east. 

(3)  That  the  most  likely  oil  horizons,  aside  from  the  Kimms- 
wick lenses  where  they  are  affected  by  pre-Mississippian  folds, 
are  local  sands  or  sandy  phases  associated  with  the  Maquoketa, 
Sweetland  Creek,  or  bituminous  phases  of  Kinderhook  shales. 

(4)  That  the  portion  of  the  region  including  southwestern 
Jersey  County  and  southern  Calhoun  County,  Illinois,  north- 
eastern Lincoln  County,  eastern  and  central  Pike  County,  and 
eastern  Ralls  County,  Missouri,  is  barren  territory. 

(5)  That  the  areas  most  favorable  structurally  are:  (a) 
closures  on  the  Lincoln  fold  where  its  axis  plunges  north  in 
Marion  and  Knox  counties,  Missouri;  (b)  a  minor  fold  on  the 
flanks  of  the  Lincoln  Fold  in  extreme  western  Pike,  Ralls,  and 
adjoining  counties  in  Missouri;  (c)  the  Pittsfield-Hadley  dome  in 


64  MISSISSIPPI  VALLEY  AREA 

Pike  County,  Illinois;  (d)  closures  associated  with  the  crest  of 
the  Pittsfield-Hadley  anticline  or  Adams  County  monocline, 
or  the  structurally  high  areas  of  the  northern  portion  of  the  area. 

(6)  That  local  sand  lenses  at  the  top  of  the  Maquoketa  are 
present  only  in  the  eastern  portions  of  Pike,  Adams  and  Hancock 
counties,  Illinois,  and  that  the  sandy  phase  of  Sweetland  Creek 
shales  is  best  developed  in  western  Ralls  and  probably  adjoining 
regions. 

(7)  That  prospecting  should  be  preceded  by  detailed  field 
and  sub-surface  work. 


CHAPTER  V— RECORDS  OF  WELLS  DRILLED  IN  THE 
MISSISSIPPI  VALLEY  AREA 

The  following  drill  records  are  considered  typical  for  the 
counties  from  which  they  come  and  will  serve  to  show  the  char- 
acter of  the  rocks  encountered  in  drilling.  Correlations  of  the 
strata  penetrated  are  those  of  the  writer  unless  otherwise  stated. 

Because  of  the  difficulty  of  distinguishing  between  the  differ- 
ent Ordovician  limestones  above  the  St.  Peter  sandstone  and 
below  the  Maquoketa  shale  in  drill  records,  the  term  "Trenton" 
is  used  to  include  the  several  limestones. 

Records  of  Wells  Located  in  Missouri 
clark  county 

Record  of  Missouri  Condensed  Milk  Factory  well  at  Kahoka1 

Thick- 
Description  of  strata  ness  Depth 

Feet  Feet 
Pleistocene  system 

Soil  and  yellow  clay 15  15 

Clay,  yellow,  drab,  and  blue 135  150 

Sand  and  gravel 11  161 

Mississippian  system 

St.  Louis  and  Ste.  Genevieve  limestones 

Limestone,  gray 9  170 

Sandstone,  soft  (water) 9  179 

Limestone,  very  fine,  gray 51  230 

Warsaw-Spergen  formation 

"Soapstone" 60  290 

Burlington- Keokuk  formation 

Limestone 110  400 

"Fire  clay" 6  406 

Limestone  with  chert ,  66  472 

Kinderhook  series 

Hannibal  and  Grassy  Creek  (Sweetland  Creek)  shales 

"Soapstone,"  blue 30  502 

Sandstone,  bluish 9  511 

Shale,  blue  gray 126  637 

"Soapstone,"  ash  color 20  657 

Shale,  brown 25  682 


»Wilson,  M.  E.,  The  occurrence  of  oil  and  gas  in  Missouri:    Missouri  Bur.  of  Geol.  and 
Mines,  Vol.  XVI,  2nd  ser.,  p.  97,  1922. 

5  (65) 


66  MISSISSIPPI  VALLEY  AREA 

Record  of  Missouri  Condensed  Milk  Factory  Well  at  Kahoka — Continued 

Thick- 
Description  of  strata  ness      Depth 

Feet        Feet 
Silurian-Devonian  systems  not  present 
Ordovician  system 
Maquoketa  shale 

Shale 85         767 

"Trenton"  limestone 

Limestone 293       1060 

St.  Peter  sandstone 

Sandstone 131       1191 


Although  no  Louisiana  limestone  is  shown  in  this  log  it  is 
probable  that  this  limestone  is  present,  at  least  in  the  eastern 
portion  of  the  county.  The  Silurian-Devonian  rocks  are  absent 
over  most  of  the  county,  but  may  be  encountered  in  the  extreme 
western  part.  . 

LEWIS    COUNTY 

Record  of  the  Canton  Oil  and  Gas  Company  well  No.  2  in  the  SW.  \i  NW.  % 

sec.  14,  T.  62  N.f  R.  6  W* 

Thick- 
Description  of  strata  ness      Depth 

Feet        Feet 
Pleistocene  system 

Loess,  clay,  and  shale        40  40 

Mississippian  system 

Burlington- Keokuk  (includes  some  Warsaw)  formations 
Limestone,  blue  to  gray,  crystalline,  white  and  blue 

chert 100         140 

Limestone,  fine  grained,  gray-blue 80         220 

Limestone,  medium  grained,  gray,  blue,  white  chert.       60         280 
Kinderhook  series 
Hannibal  shale 

Shale,  gray,  uniform 50         330 

Shale,  sand,  greenish .       40         370 

Louisiana  limestone 

Limestone,  gray,  brown,  fine  grained 50         420 

Grassy  Creek  (Sweetland  Creek)  shale 

Shale,  bluish  gray 40         460 

Silurian-Devonian  systems  not  present 
Ordovician  system 
Maquoketa  shale 

Shale,  clayey,  dark  gray 20         480 

No  record 65         545 


•Idem,  p.  96. 


RECORD  OF  WELLS  67 

Record  of  the  Canton  Oil  and  Gas  Company  well  No.  2  in  the  SW.  %  NW.  \i 
sec.  14,  T.  62  N.,  R.  6  W—  Continued 

Thick- 
Description  of  strata  ness      Depth 

1  Feet        Feet 
Ordovician  system — Continued 
"Trenton"  limestone 

Limestone,   light  to  dark  gray,   fine  grained,  more 

crystalline  towards  base 175         720 

Limestone,  light  gray,  very  hard,  fine  grained 30         750 

Limestone,  magnesian,  fine  grained,  brown  and  hard.  60         810 

No  record 70         880 

Limestone,  almost  non-magnesian : 15         895 

St.  Peter  sandstone 

Sandstone,  white,  coarse  graiujd 33         928 

The  above  log  is  typical  for  most  of  the  county,  but  to  the 
west  and  especially  the  southwest,  limestones  of  Devonian  age 
may  be  expected  between  the  Maquoketa  and  Grassy  Creek 
(Sweetland  Creek)  shales.  The  limestone  at  370  feet  is  somewhat 
thicker  and  lower  in  the  section  than  would  be  expected  from  a 
study  of  the  outcrops  farther  south,  but  this  may  be  due  to  an 
error  in  logging  the  well. 

LINCOLN    COUNTY 

Record  of  Prairie  Oil  and  Gas  Company  well  at  Moscow  Mills* 

Thick- 
Description  of  strata  ness     Depth 

Feet        Feet 
Pleistocene  system 

Soil  and  clay 8             8 

Hardpan,  yellow 4           12 

Pennsylvanian  system  (?) 

Soapstone,  blue 40           52 

Mixed  gravel  (water) 3           55 

Mississippian  (?)  system 

Sandstone,  white,  hard 25           8Q> 

Keokuk-Burlington  and  Chouteau  formations 

Limestone,  brown,  cherty 260         340 

Hannibal    and    Maquoketa    shale    with    possibly    some 
Devonian 

Soapstone,  blue,  soft 10         350 

Limestone,  brown 72         422 

Shale,  brown . 3         425 

Kimmswick  ("Trenton")  limestone 

Limestone,  brown  and  white 95         520 

Sandstone,  yellow,  hard 15         525 

Limestone,  brown,  hard 126         661 

St.  Peter  sandstone 

Sandstone 79        740 

» Idem,  p.  100. 


68  MISSISSIPPI  VALLEY  AREA 

Record  of  William  Overall  well  in  SE.  }4,  sec.  1,  T.  49  N.,  R.  1  E. 

Thick- 
Description  of  strata  ness      Depth 

Feet        Feet 
Pleistocene  system 

Soil,  light,  ashy 2  2 

Hardpan 3  5 

Clay,  light  brown 10  15 

Soapstone,  gray  streaks  of  sand 27  42 

Pennsylvanian  system 

Soapstone,  dark  blue 94         136 

Mississippian  system 

Burlington-Chouteau  formation 

Limestone,  brown '    54         190 

Limestone,  blue. 30         220 

Hannibal  shale 

Shale,  dark 35         255 

Ordovician  system 
Maquoketa  shale 

Shale,  dark  blue 40         295 

"Trenton"  formation 

Limestone,  gray 155         450 

Limestone  with  shale '.  . .  .      115         565 

Sandstone,  hard 12         577 

Limestone,  gray 18         595 

St.  Peter  sandstone 

Sandstone 61         656 

In  correlating  the  above  log  the  writer  took  the  liberty  of 
separating  the  75-foot  dark  shale  formation  into  two  portions, 
the  upper  35  feet  of  which  is  referred  to  the  Hannibal,  while  the 
lower  portion  is  referred  to  the  Maquoketa.  The  separation  is 
based  on  observations  of  outcrops  about  a  mile  northwest  of  the 
well  which  show  Hannibal  shale  resting  on  Maquoketa.  Locally 
in  this  same  vicinity  Devonian  limestone  as  much  as  12  feet 
thick  comes  in  between  the  Hannibal  and  Maquoketa  shales. 

MARION    COUNTY 

Record  of  well  at  Palmyra 

Thick- 
Description  of  strata  ness      Depth 

Feet        Feet 
Mississippian  system 

Burlington  limestone 

Limestone,  brownish 20  20 

Limestone,  finer 11  31 

Kinderhook  series 

Hannibal  (?)  formation 

Sand,  gray 34  65 


RECORD  OF  WELLS  69 

Record  of  well  at  Palmyra — Continued 

Thick- 
Description  of  strata  ness      Depth 

Feet        Feet 
Mississippian  system — Continued 
Louisiana  limestone 

Limestone 25  90 

Grassy  Creek  (Sweetland  Creek)  shale 

Clay,  light  blue 70         160 

Silurian-Devonian  systems  missing 
Ordovician  system 
Maquoketa  shale 

Clay,  dark  olive,  little  limestone 125         285 

("Trenton")  limestone 

Limestone,  dove  color 15         300 

Limestone,  light  gray,  compact 55         355 

Limestone,  compact,  dove  color. 15         370 

Limestone  and  quartz  (?)  crystals 190         560 

Limestone,  impure  light  and  dark  gray 40         600 

St.  Peter  sandstone 

Sand,  fine 100         700 

It  is  probable  that  some  of  the  shale  included  in  the  Ma- 
quoketa belongs  with  the  Kinderhook.  While  the  above  log  will 
serve  to  give  an  idea  of  the  character  and  thickness  of  the  forma- 
tions in  the  eastern  portion  of  the  county,  it  is  known  from  out- 
crops and  well  records  that  in  the  western  portion  of  the  county 
the  Devonian  system  is  present  and  is  represented  by  limestone 
which  may  reach  a  thickness  of  80  feet  or  possibly  a  little  more. 

The  following  logs  from  the  vicinity  of  Nelsonville  in  north- 
western Marion  County  and  from  the  Jacksonville  well  at  Monroe 
City  in  eastern  Monroe  County  afford  a  general  ide'a  of  the  strata 
penetrated  in  drilling  to  the  St.  Peter  sandstone  in  western 
Marion  County. 

Record  of  C.  H.  Mohr  well  near  Nelsonville  in  sec.  21,  T.  59  N.,  R.  8  W* 

Thick- 
Description  of  strata  ness      Depth 

Feet        Feet 
Pleistocene  system 

Clay 45  45 

Mississippian  system 
Kinderhook  series 
Hannibal  shale 

Shale,  blue 150         195 

Louisiana  limestone 

Limestone 60         255 

Grassy  Creek  (Sweetland  Creek)  shale 

Shale,  gray 35         290 


<Idem,  p.  101.  Wilson,  M\  E.,  The  occurrence  of  oil  and  ga    i  i  Missouri;  Missouri  Bur. 
of  Geol.  and  Mines,  Vol.  XVI,  2nd  ser.,  p.  101,   1922. 


70  MISSISSIPPI  VALLEY  AREA 

Record  of  C.  H.  Mohr  well  near  Xelsonville  in  sec.  21,  T.  59,  59  V.,  R.  S  W. — 

Continued 

Thick- 
Description  of  strata  ness      Depth 

Feet        Feet 
Devonian  system  (including  some  "Trenton"  limestone) 

Limestone 220         510 

Ordovician  system 

"Trenton"  limestone 

Sandstone,  red 15         525 

Limestone 125         650 

St.  Peter  sandstone 

Sandstone,  white,  mineral  water 10         660 

Rock,  hard 2         662 

Sand  and  limestone 213         S75 

Lack  of  detail  in  the  above  log  makes  correlation  difficult, 
but  suggested  correlations  indicate  the  writer's  interpretation  of 
the  log. 

MONROE    COUNTY 

Record  of  Jackson  well  at  Monroe  City 

Thick- 
Description  of  strata  ness      Depth 

Feet        Feet 
Pleistocene  system 

Gravel 17  17 

Fire  clay 19  36 

Mississippian  system 

Burlington  and  Chouteau  formations 

Lime,  white 36  72 

Sand,  white 7S  150 

Lime,  brown 25         175 

Hannibal  shale  (?) 

Shale,  blue 110         2S5 

Louisiana  limestone 

Lime,  brown 24         309 

Lime,  light  brown 6         315 

Grassy  Creek  (?)  shale  (Sweetland  Creek) 

Mud,  blue 16         331 

Devonian  (?)  system 

Lime,  gray 39         370 

Lime,  white 6         376 

Lime,  blue -17         423 

Ordovician  system 

Trenton  limestone  (?) 

Lime,  white 29         452 

Oil  sand 6         458 

Lime,  white 59         517 

Shale,  light  brown 34         554 

Lime,  gray 2         556 


RECORD  OF  WELLS 


71 


Record  of  Jackson  well  at  Monroe  City — Continued 

Thick- 
Description  of  strata  ness  Depth 

Feet  Feet 
Ordovician  system — Continued 

Water  sand 5  561 

Blue  shale 4  565 

Lime,  gray 25  590 

St.  Peter  sandstone  (?) 

Sand,  white 85  675 

Sand,  blue 95  760 


PIKE    COUNTY 

Record  of  Roberts  well,  Clarhsville* 

Thick- 
Description  of  strata  ness      Depth 

Feet        Feet 
Pleistocene  system 

Clay 75  75 

Mississippian  system 

Burlington-Chouteau  formations 

Limestone,  crystalline,  gray,  cherty . 25         100 

Kinderhook  series 
Hannibal  shale 

Shale,  bluish-gray 100         200 

Louisiana  limestone 

Limestone,  fine  grained,  light  to  dark  gray 40         240 

Grassy  Creek  shale  (Sweetland  Creek) 

Shale,  dark  blue 10         250 

Silurian  system 

Limestone,  brown  to  white,  fine  grained 20         270 

Ordovician  system 
Maquoketa  shale 

Shale,  gray  to  bluish-gray,  calcareous 75         345 

Limestone,  argillaceous,  sandy  and  dove-colored ....       95         440 
Kimmswick-Plattin  ("Trenton")  limestone 

Limestone 310         750 

St.  Peter  sandstone 

Sandstone,  well  rounded  grains 83         833  + 


The  Kimmswick  ("Trenton")  makes  up  the  surface  rock 
over  most  of  eastern  Pike  County,  but  in  the  central  and  western 
portions  Mississippian  rocks  are  found  at  the  surface.  From 
this  region  the  following  well  records  from  Bowling  Green  may 
be  considered  typical. 


•Idem,  p.  100. 


72  MISSISSIPPI  VALLEY  AREA 

Record  of  well  at  Bowling  Green 

Thick- 
Description  of  strata  ness      Depth 

Feet        Feet 
Pleistocene  system 

Soil  and  drift -. 70           70 

Clay,  dark  red 6           76 

Missing 14           90 

Mississippian  system 

Burlington  limestone 

Limestone,  cherty 10         100 

Limestone,  yellow,  some  chert 15         115 

Kinderhook  series 
Chouteau  limestone 

Limestone,  cream  colored,  fine  grained .  25         140 

Limestone,  dark  gray 15         155 

Hannibal  shale 

Shale,  dark  gray,  calcareous 10         165 

Shale,  blue  gray 85         250 

Missing 5         255 

Shale,  gray 2         257 

Silurian  system 
Alexandrian  series 

Limestone,  argillaceous,  light  gray 1         258 

Limestone,  argillaceous,  dark  gray 7         265 

Limestone,  argillaceous,  light  gray 10         275 

Sandstone,  impure 1         276 

Limestone,  sandy,  dark 4         280 

Ordovician  system 
Maquoketa  shale 

Limestone,  argillaceous,  light  gray-green 10         290 

Limestone,  argillaceous,  dark  gray-green 50         340 

Limestone,  sandy,  brown 5         345 

Limestone,  sandy,  brown,  fine-grained 5         350 

"Trenton"  limestone 

Limestone,  dark  gray 30         380 

Limestone,  light  gray 70         450 

Limestone,  cream 70         520 


RALLS    COUNTY 

The  "Trenton"  makes  up  the  surface  rock  over  most  of  the 
central  portion  of  the  county  and  it  is  only  in  the  western  and 
northern  portions  that  these  formations  are  buried  to  an  appre- 
ciable depth.  To  the  north  and  west  the  formations  between  the 
surface  and  the  St.  Peter  will  be  similar  to  those  of  Marion  county, 
and  to  the  south  they  will  be  like  those  of  Pike  county.  The 
following  logs  are  available  for.  northern  and  western  Ralls 
county,  but  they  show  no  detail  and  the  writer  is  of  the  opinion 
that  they  are  inaccurate. 


RECORD  OF  WELLS  73 

Record  of  T.  E.  Allison  well  at  Perry1 

Thick- 
Description  of  strata  ness      Depth 

Feet        Feet 
Pleistocene  system 

Dirt 2             2 

Flint  rock  and  boulders 20           22 

Limestone 12           34 

"Soapstone"  shale 126         160 

Limestone,  white 10         170 

Shale,  red,  "soapy" 50         220 

"Soapstone"  shale '. 210         430 

Limestone,  gray  to  brown 48         478 

Sandstone,  white,  coarse 12         490 

ST.   CHARLES    COUNTY 

Record  of  R.  D.  Silver  well,  near  St.  Peters8 

Thick- 
Description  of  strata  ness      Depth 

Feet        Feet 
Pleistocene  system 

Alluvium 25           25 

Mississippian  system 

Meramec  series  with  possibly  some  Keokuk 

Limestone,  fine-grained,  gray  chert 115         140 

Osage  series  and  Chouteau 

Limestone,  gray  to  white,  coarsely  crystalline 140         280 

Limestone,  gray,  finely  crystalline 119         399 

Kinderhook  series 
Hannibal  shale 

Shale,  gray  to  brown,  sandy 38         437 

Ordovician  system 

"Trenton"  limestone 

Limestone,  gray  to  white,  coarsely  crystalline 105         542 

Limestone,  dark  gray,  fossiliferous 49         591 

Limestone,  gray  to  drab 151         742 

Dolomite,  brown  to  gray .56         798 

St.  Peter  sandstone 

Sandstone,  white,  rounded  grains 202       1000 

Record  of  McMenarny  Bros,  well,  sec.  86,  T.  48  N.,  R.  2  E. 

Thick- 
Description  of  strata  ness      Depth 

Feet        Feet 
Pleistocene  system 

Soil,  ashy  color 3             3 

Clay,  brown,  yellowish 41           44 

Soapstone,  blue 12           56 


'Wilson,  M.  E.,  Oil  and  gas  possibilities  in  Missouri.:  Mo.  Bur.  of  Gool.  and  Mines, 
Vol.  XVI,  p.  101,  1922. 

8Wilson,  M.  E.,  Oil  and  gas  possibilities  in  Missouri.  Mo.  Bur.  of  Geol.  and  Mines,  Vol. 
XVI,  p.  98,  1922. 


74  MISSISSIPPI  VALLEY  AREA 

Record  of  McMenarny  Bros,  well,  sec.  86,  T.  4.8  N„  R.  2  E. — Continued 

Thick- 
Description  of  strata  ness      Depth 

Feet        Feet 
Mississippian  system 
Osage  series 

Limestone,  soft  gray,  chert 49         105 

Limestone,  white,  chert 200         305 

Kinderhook  series 
Chouteau  formation 

Missing. 25         330 

Limestone,  dark  gray  to  blue 40         370 

Hanhibal  shale 

Shale,  calcareous,  greenish-blue 15         385 

Shale,  blue  gray 15         400 

Missing 15         415 

Ordovician  system 

"Trenton"  limestone 

Limestone,  white  to  brown 125         540 

Limestone,  blue,  shaly 30         570 

Limestone,  gray,  fine-grained 110         680 

Limestone,  gray  drab 70         750 

St.  Peter  sandstone 

Sandstone 60         810 


Records  of  Wells  Located  in  Illinois 
adams  county 

Record  of  S.  A.  Hubbard  well  near  Quincy,  sec.  16,  T.  1  S.,  R.  9  W. 

Thick- 
Description  of  strata  ness      Depth 

Feet        Feet 
Pleistocene  system  v 

Alluvium,  sand  and  clay 124         124 

Mississippian  system 
Louisiana  limestone 

Limestone,  lithographic 30         154 

Sweetland  Creek  (Grassy  Creek)  shale 

Shale,  blue  gray,  sandy 60         204 

Ordovician  system 
Maquoketa  shale 

Shale,  blue 96         310 

"Trenton"  limestone 

Limestone,  dense  to  granular,  white-brown 307         617 

St.  Peter  sandstone 

Sandstone,  gray 138         755 


RECORD  OF  WELLS  75 

Record  of  Johnson  well  near  Brown  County  line  in  sec.  24,  T.  2  S.,  R.  5  W. 

Thick- 
Description  of  strata  ness      Depth 

Feet        Feet 
Pleistocene  system 

Clay  and  gravel 14  14 

Mississippian  system 
Meramec  series 

Limestone,  gray 24  38 

Shale,  blue,  thin  streaks  of  shells 90         128 

Burlington-Keokuk  formation 

Limestone",  white 220         348 

Kinderhook  series 

Hannibal  and  Sweetland  Creek  (Grassy  Creek)  shale 

Shale,  green 25         373 

Shale,  blue 40         413 

Shale,  black 120         533 

Silurian-Devonian  systems 

Lime,  gray 30         563 

Ordovician  system 
Maquoketa  shale 

Shale,  blue 27         590 

Shale,  gray,  with  sand  streaks 40         630 


CALHOUN    COUNTY 

Record  of  Kinscheff  well  near  Kampsville,  sec.  10,  T.  9  S.,R.  2  W. 

Thick- 
Description  of  strata  ness      Depth 

Feet        Feet 
Pleistocene  system 

Soil,  clay,  and  gravel 42  42 

Mississippian  system 
Kinderhook  series 

Sweetland    Creek    (Grassy    Creek)    shale   and   Louisiana 
limestone? 

Limestone,  hard  and  broken 5  47 

Shale,  gray  to  blue 36  83 

Silurian-Devonian  systems 

Limestone 8  91 

Limestone,  with  shale  bands 7  OS 

Limestone 103         201 

Ordovician  system 
Maquoketa  shale 

Shale,  blue 84         285 

Shale,  hard,  gray,  lime  bands 20         305 

Shale,  blue,  with  lime  bands 63         368 

"Trenton"  limestone 

Limestone 340         70S 

St.  Peter  sandstone 

Sandstone L45         S53 


76  MISSISSIPPI  VALLEY  AREA 


HANCOCK    COUNTY 

Record  of  Popel-Giller  Brewing  Company  well  at  Warsaw 

Thick- 
Description  of  strata  ness      Depth 

Feet        Feet 
Pleistocene  system 

Soil  and  clay  drift 40  40 

Mississippian  system 

Warsaw  formation 

Limestone,  blue,  and  shale 15  55 

Burlington-Keokuk  formation 

Lime  rock,  blue 50         105 

Lime  and  grit 25         130 

Grit  and  fire  clay 10         140 

Limestone,  gray 45         185 

Hannibal  shale 

"Soapstone,"  blue 30         215 

Sandstone 19         234 

Louisiana  limestone 

Rock,  lithograph,  light 46         280 

Rock,  lithograph,  dark 10         290 

Limestone,  bastard 6         296 

Sweetland  Creek  (Grassy  Creek)  shale 

"Soapstone" \        69         365 

Shale,  brown 40         405 

Maquoketa  (Cincinnati)  shale 

Shale,  brown 99         504 

"Trenton"  limestone 

Limestone,  brown 126         630 

St.  Peter  sandstone0 

Sandstone,  brown 182         812 


alt  is  probable  that  some  of  the  rock  included  with  St.  Peter  sandstone  is  a  dolomitic 
limestone  and  should  be  included  with  the  "Trenton." 


Record  of  McCune  well  near  West  Point  in  SE.   \i,  SE.   %,  sec.  16,  T.  8  N.t 

R.  7  W. 

Thick- 
Description  of  strata  ness      Depth 

Feet        Feet 
Pleistocene  system 

Drift 147  147 

Mississippian  system 

Burlington-Keokuk  formation 

Limestone,  coarse,  blue,  fossiliferous,  changes  to  buff 

limestone,  then  to  blue  shaly  limestone 219         366 

Kinderhook  series 

Hannibal  and  Sweetland  Creek  (Grassy  Creek)  shale 

Shale,  gray,  thin  bedded 235         601 


RECORD  OF  WELLS  77 

Record  of  McCune  well  near  West  Point  in  SE.   H,  SE.   H,  sec.  16,  T.  3  N., 

R.  7  W—  Continued 

Thick- 
Description  of  strata  ness        Depth 

Feet         Feet 
Silurian-Devonian  systems 

Limestone,  gray  to  buff,  with  some  shale  near    the 
bottom;  in  the  bottom  a  few  sand  grains  (clear 

colorless  angular,  slightly  rounded  grains) 89         690 

Ordovician  system 
Maquoketa  shale 

Shale,  gray 42         732 

"Trenton"  dolomite 

Dolomite,  buff,  fine  grained 220         952 

JERSEY    COUNTY 

Record  of  City  Waterworks  well  at  Jerseyville 

Thick- 
Description  of  strata  ness  Depth 

Feet  Feet 
Pleistocene  system 

jt  ;     Clay 26  26 

Pennsylvanian  system 

Slate,  black 74  100 

Mississippian  system 
Meramec  series 

Lime,  flinty 16  116 

Slate 24  140 

Lime 5  145 

Slate 23  168 

Lime 12  180 

Slate. 27  207 

Lime 10  217 

Slate 4  .221 

Osage  series  and  Chouteau  limestone 

Lime 229  450 

Flint 30  480 

Lime 50  530 

Kinderhook  series 
Hannibal  shale 

Slate 25  555 

Lime 10  565 

Slate 10  575 

Silurian-Devonian  systems 

Lime,  hard 65  640 

Slate 10  650 

Lime  and  flint 160  810 

Ordovician  system 
Maquoketa  shale 

Slate 80  890 

Lime 50  940 

Slate 35  975 


78  MISSISSIPPI  VALLEY  AREA 

Record  of  City  Waterworks  well  at  Jerseyville — Continued 

Thick- 
Description  of  strata  ness      Depth 

Feet        Feet 
Ordovician  system — Continued 
"Trenton"  limestone 

Lime 387       1362 

St.  Peter  sandstone 

Sandstone 180       1542 


PIKE   COUNTY 

Record  of  Ducey  well  near  Piltsfield  in  sec.  29,  T.  5  S.,  R.  4  W. 

Thick- 
Description  of  strata  ness      Depth 

Feet        Feet 
Pleistocene  system 

Soil  and  drift , 36  36 

Mississippian  system 

Burlington  limestone 

Limestone 65         101 

Kinderhook  series 

Hannibal  and  Sweetland  Creek  (Grassy  Creek)  shales 

Shale 140         241 

Silurian-Devonian  systems 

Limestone 64         305 

Ordovician  system 
Maquoketa  shale 

Shale 138         443 

"Trenton"  limestone 

Limestone 298         741 

St.  Peter  sandstone 

Sandstone '.         8         740 


INDEX 


A  PAGE 

Adams    County,     Illinois,   Hoing 

sand  in 62 

Maquoketa  shale  in 24 

Meramec  series  in 40 

oil  possibilities  in 59 

Pennsylvanian  system  in 44 

Pittsfield-Hadley  anticline  in. .     49 

record  of  wells  drilled  in 74-75 

sand  lenses  of  the  Maquoketa  in   64 

Silurian  formations  in 62 

St.  Louis  and  Ste.   Genevieve 

formations  in 42,  43 

structures  in 49,  59,  61,  64 

topographic  maps  for 7 

Alexandrian     series,     description 

of ■.  ..24r-28 

Allison,  T.  E.,  record  of  well  of . .     73 
Alton,  outcrop  of  St.  Louis  and 
Ste.    Genevieve    formations 

near .  42,  43 

Apex,  Kimmswiek  limestone  near    22 
outcrops  of  Plattin  limestone 

near 20 

Artesian  wells  in  St.  Peter  forma- 
tion  ..17-18 

Asphalt  in  Kimmswiek  and  Edge- 
wood  formations 58 

Atlas,  outcrop  of  Sweetland  Creek 

shale  near 34 

Auburn  chert,  description  of ...  .     21 

6 

Barograph,  use  of. 6 

Batchtown,  outcrops  of  Kimms- 
wiek limestone  in 21 

Bedford,  description  of  Pittsfield- 
Hadley  anticline  near 46,  49 

Louisiana  limestone  near 35 

Sweetland  Creek  shale  near ...  34 
Bowling  Green,  Cyrene  limestone 

near 26 

Devonian  limestone  near 31 

Edgewood  formations  near. ...  25 

record  of  well  at 72 

Bowling  Green  dolomite,  descrip- 
tion of.. . 24-27 


PAGE 

Brassfield   limestone,   correlation 

of 24 

Brush  Creek,  description  of 

Sweetland  Creek  shale  in .  .  .     33 

Brussels,  syncline  near 46,  49 

Buehler,  H.  A.,  acknowledgment 

of  indebtedness  to 5 

Burlington  formation,    elevation 

of 8-14 

oil  and  gas  in 58 

reservoirs  in. 61 

use  of  as  key  horizon 7,  45 

Burlington  -  Keokuk    limestone, 

description  of 38,  39 

distribution  of 38-39 

C 

Calhoun   County,   Illinois,    anti- 
clinal fold  in 45 

Bowling  Green  dolomite  in. .  . .     27 
Burlington-Keokuk  limestone 

in 38 

Cap-au-Gres  fault  in 16 

Chouteau  limestone  in 37 

Devonian  outcrops  in 29,  31 

Joachim  dolomite  in 19 

Kimmswiek  limestone  in 21-22 

Lincoln  fold  in 47 

.    Louisiana  limestone  in 35 

Maquoketa  shale  in 22,  23,  24 

oil  possibilities  in 63 

Ordovician  formations  in  ...  .  16-24 

outcrops  in 15 

Pennsylvanian  system  in 44 

Plattin  limestone  in 20-21 

Quaternary  system  in 44 

record  of  well  drilled  in* 75 

Sexton  Creek  limestone  in .  .  .  27-28 

Silurian  outcrops  in 24 

St.   Louis  and  Ste.   Genevieve 

formations  in 42,  43 

St.  Peter  formations  in 18 

Tertiary  system  in 44 

topographic  maps  for 7 

Sweetland  CreeK  shale  in 34 

Callaway   limestone,    description 

of 29 


79 


80 


INDEX 


PAGE 

Canton,    description    of    western 

Adams  County  terrace  near.  49 
exposure    of    Warsaw-Spergen 

formation  near 41 

Canton  Oil  and  Gas  Company, 

well  of 66-67 

Cap  -  au  -  Gres  fault,  description 

of .16,  46 

in  Calhoun  County,  Illinois.  .  .  16 

relation  to  Lincoln  fold 47 

Capillarity,  effect  of  in  migration 

of  oil 55-56 

Carlinville,  production  of  oil  near  54 
Carthage,  description  of  fold  near  50 
Cedar  Creek,  outcrop  of  Sweet- 
land  Creek  shale  along 33 

Cedar  Valley  limestone,  correla- 
tion of 28 

Center,  terrace  near 59 

Chautauqua,     outcrop     of     Fern 

Glen  formation  near 38 

Chouteau  limestone,   description 

of 37 

distribution  of 37 

reservoirs  in 61 

Clark    County,    Missouri,    anti- 
clines in 61 

description  of  western  Adams 

County  terrace  in 49 

Keokuk  -  Burlington  limestone 

in 39 

Meramec  series  in 39 

oil  possioilities  in 60 

Penns^lvanian  system  in 43 

record  of  well  in 65—66 

St.   Louis  and  Ste.   Genevieve 

formations  in 42,  43 

structures  in 59 

topographic  maps  for 7 

Warsaw-Spergen  formations  in  41 
Clarksville,  absence  of  Devonian 

limestone  near 29 

record  of  Roberts  well  at 71 

Sexton  Creek  limestone  near .  .  27 

Cliff  dale,  Hannibal  shale  near.  .  .  36 

Cooper  limestone,  description  of.  29 
Cuivre  River,  occurrence  of  Cy- 

rene  limestone  in 26 

Cyrene,     occurrence    of    Cyrene 

limestone  near 26 

Cyrene  dolomite,  description  of. 24-26 


D  ,         PAGE 

Dallas,  Burlington-Keokuk  lime- 
stone near 38 

Dameron,  occurrence  of  Bowling 

Green  dolomite  near 27 

Sexton  Creek  limestone  near. .      27 

Devonian  limestone,  at,  in  or 
near: 

Bowling  Green 31 

Calhoun  County,  Illinois.  .  .  .29,  31 

Grafton 31,  32 

Hamburg 31 

Hardin 31,  32,  34 

Jersey  County,  Illinois 29,  32 

Lincoln  County,  Missouri. 21,  31,  32 

Louisiana 31 

Marion  County,  Missouri. ...  29,  30 

Meppin 31 

New  London. 30 

North  River 30 

Nutwood. 31,  32 

Pike  County,  Missouri 29-31 

Ralls  County,  Missouri.22, 29, 31, 32 

Sees  Creek 30 

Shiel 30 

deformation  of 52 

deposition  of 52 

distribution  of 29,  62 

elevation  of 12 

oil  in 58 

Devonian  system,  description  of  .28-32 

Deformation,  effect  of  in  accumu- 
lation of  oil 56-57 

Deformation,  periods  of 50-53 

DeWolf,  F.  W-,  acknowledgment 

of  indebtedness  to 5 

Dogtown  Landing,  St.  Peter  out- 
crops near 18 

Ducey  well  near  Pittsfield,  record 

of 78 

E 

Edgewood,  Cyrene  limestone  near     26 
outcrop    of    Plattin   limestone 
near 20 

Edgewood  dolomite,  asphaltic  re- 
siduum in 58 

description  of 24-27 

Ekblaw,  George,  work  of 5,  6 

Everton  formation,  description  of     17 


INDEX 


81 


F  PAGE 

Fall  Creek,  Hannibal  shale  near.  37 
Fern  Glen  formation,  description 

of 38 

distribution  of 38 

Flint  Hill  church,  exposure  of  De- 
vonian limestone  near 29-30 

Foley,  Jefferson  City  formations 

near 17 

Joachim  dolomite  in  bluff  near .  19 

St.  Peter  formations  near 18 

G 

Gas  pressure,  effect  of  in  migra- 
tion of  oil 55-56 

Geodes,  oil-bearing,  description  of     58 
Gilead,   Sexton   Creek  limestone 

near 27 

Grafton,  anticlinal  fold  near. ...     45 
Burlington-Keokuk    limestone 

near 38 

Devonian  limestone  near.  .  .  .31,  32 

Fern  Glen  formation  near 38 

Hannibal  shale  near 36 

Kimmswick  outcrops  near.  ...      47 

Pennsylvanian  shale  near 47 

Silurian  limestone  near 24,  46 

St.  Louis  limestone  near 41,  47 

Sweetland  Creek  shale  near.  . .     34 
Grassy  Creek,  description  of  sec- 
tions  of    Silurian   formation 

along 25 

occurrence  of  Noix  oolite  in.  .23,  25 
Grassy  Creek  (Sweetland  Creek) 

shale,  correlation  of 28 

description  of 33-34 

See  also  Sweetland  Creek  shale. 
Gravity,  effect  of  in  migration  of 

oil 55-56 

Greens  Bottom,  exposure  of  War- 

saw-Spergen  formations  near     41 
Gregory,   description  of  western 

Adams  County  teirace  near.      49 

H 

Hamburg,  absence  of  Sweetland 

Creek  shale  near 34 

Chouteau  limestone  near 37 

Devonian  limestone  near 31 

Hannibal  shale  near 36 

Kimmswick  limestone  near. ...  21 

Louisiana  limestone  near 35 

outcrop  of  Noix  oolite  near. ...  24 

Sexton  Creek  limestone  near .  .  28 

Hamilton  shale,  correlation  of .  .  .  23 
6 


PAGE 

Hancock  County,   Illinois,   anti- 
cline in <61 

Burlington-Keokuk    limestone 

in 38,  39 

Hoing  sand  in 62 

Meramec  series  in 40 

oil-bearing  geodes  in 58 

oil  possibilities  in 60,  62 

Pennsylvanian  system  in 44 

production  of  oil  in 54 

record  of  wells  drilled  in 76-77 

sand  lenses  of  Maquoketa  shale 

in 64 

Silurian  formations  in 62 

St.    Louis-Ste.    Genevieve  for- 
mations in 42,  43 

structures  in 50,  59 

topographic  maps  for 7 

Warsaw-Spergen  formation  in. 40,  41 

Hannibal,  observations  near 6 

Louisiana  limestone  near 34 

occurrence   of   Hannibal    shale 
near 35-36 

Hannibal  shale,  description  of.  .35-37 

distribution  of 35-37 

elevation  of 8-14 

Hardin,    absence    of    Sweetland 

Creek  shale  near 34 

Chouteau  limestone  near.  .  .  .34,  37 
Devonian  limestone  near. 31,  32,  34 

Hannibal  shale  near 34 

Louisiana  limestone  near.  .  .  .34,  35 
Sexton  CreeK  limestone  near .  .      27 

Henderson    County,    Illinois,    oil 

possibilities  in 62 

Hoing  sand,  distribution  of '62 

lenses  in 61 

Hubbard,  record  of  well  drilled  for     74 

I 

Illinois,  record  of  wells  drilled  in. 74-78 

J 

Jacksonville,    production    of    oil 

near 54 

Jefferson  City  formations,  at,  in 
or  near: 

Foley 17 

Lincoln  County,  Missouri . . 

16-17,  47 

Sandy  Creek 16 

description  of 16-17 

lack  of  oil  in 16 

outcrops  of 16-17 


82 


INDEX 


PAGE 

Jefferson   County,    Missouri,    St. 

Peter  formation  in 17 

Jersey  County,  Illinois,  absence  of 

Noix  oolite  in 25 

anticlinal  fold  in 45 

Bowling  Green  dolomite  in. .  .  .      27 

Cap-au-Gres  fault  in 46 

Chouteau  limestone  in 37 

Devonian  outcrops  in 29,  32 

Fern  Glen  formation  in 38 

Hannibal  shale  in 36 

Kimmswick  limestone  in 21 

Lincoln  fold  in 47 

Louisiana  limestone  in 35 

Maquoketa  shale  in .22,  23 

Meramec  seiies  in 40 

oil  possibilities  in 63 

Ordovician  formations  in  ...  .  16-24 

outcrops  in 15 

record  of  well  drilled  in 77-78 

Sexton  Creek  limestone  in  ...  .      27 

Silurian  outcrops  in 24 

St.    Louis-Ste.    Genevieve   for- 
mations in. .  .  . 42,  43 

Sweetland  Creek  shale  in 34 

Warsaw-Spergen  formations  in.     41 

Jerseyville,  record  of  City  Water 

Works  well  at 77-78 

Joachim  dolomite,  description 

of 19-20 

distribution  of 19-20 

elevation  of 11-12 

Johnson  well  in  Adams  County, 

Illinois,  record  of 75 

K 

Kahoka,  record  of  well  at 65—66 

Kampsville,  record  of  well  drilled 

near 75 

Keokuk  formation,  elevation  of.. 8-14 
See  also  Burlington- Keokuk. 

Kimmswick     ("Trenton")     lime- 
stone, asphaltic  residuum  in .      58 

deformation  of 60 

deposition  of 51 

description  of 21-22 

distribution  of 21-22 

elevation  of 9-14 

occurrence  of  Receptaculites  in.     22 
oil  possibilities  of.  .51,  54,  58,  62,  63 

reservoirs  in 61 

tilting  of 51 

wells  penetrating 7 


PAGE 

Kinderhook,    Fern    Glen    forma- 
tion near 38 

Hannibal  shale  near 37 

Kinderhook  series,  description 

of ' 33-37,  63 

Kinderhook  shale,  oil  possibilities 

of 58,  63 

Kinseheff  well  in  Calhoun  County, 

record  of 75 

Kissinger,  Burlington-Keokuk 

limestone  in  bluff  near 38 

Knox  County,  Missouri,   absence 

of  Maquoketa  shale  in 22 

oil  possibilities  in 63 

L 

LaGrange,  description  of  western 

Adams  County  terrace  near.      49 
Pittsfield-Hadley     anticline 

near 46,  49 

Lewis    County,    Missouri,    anti- 
clines in 61 

Burlington  -  Keokuk  limestone 

in 39 

description  of  western  Adams 

County  terrace  in 49 

Meramec  series  in 39 

Pennsylvanian  system  in 43 

Pittsfield-Hadley  anticline  in .  .      49 

record  of  well  drilled  in 66-67 

St.    Louis-Ste.    Genevieve   for- 
mations in 42,  43 

structures  in 50 

topographic  maps  of 7 

Lick  Creek,  Louisiana  limestone 

in 34 

Lincoln    County,    Missouri,    ab- 
sence of  Noix  oolite  in 25 

anticlinal  fold  in 45,  47 

Bowling  Green  dolomite  in. .  .  .     27 
Burlington  -  Keokuk  limestone 

in 39 

Cap-au-Gres  fault  in . 21 

Chouteau  limestone  in 37 

Cyrene  limestone  in 26 

determination  of  elevations  in.        7 
Devonian  outcrops  in. .  .  .29,  31,  32 

Fern  Glen  formation  in 38 

Hannibal  shale  in 36 

Jefferson  City  formations  in. .  16-17 

Joachim  dolomite  in 19-20 

Kimmswick  limestone  in 21-22 

Maquoketa  shale  in 22 


INDEX 


83 


PAGE 

Meramec  series  in 39 

oil  possibilities  n 59,  63 

Ordovician  formations  in ...  .  16-24 

outcrops  in 15 

Pennsylvanian  system  in 43 

Plattin  limestone  in 20-21 

Quaternary  system  in 44 

record  of  well  drilled  in. ....  .  67-68 

Sexton  Creek  limestone  in ...  .      27 

Silurian  outcrops  in 24 

St.  Peter  formations  in 18 

syncline  in 49 

topographic  maps  for 7 

Lincoln  fold,  description  of 45-48 

oil  possibilities  of 58,  59-60,  63 

Lingulas  in  Maquoketa  shale,  oc- 
currence of 23 

Louisiana,  Bowling  Green  dolo- 
mite near 27 

Devonian  limestone  near 31 

Louisiana  limestone  near .....      34 

Noix  oolite  near 25 

Sweetland  Creek  shale  near.  .  .      33 

Louisiana  limestone,   description 

of 34-35,  63 

distribution  of 34-35 

Lower  Mississippian  sub-system, 

description  of 32-43 

M 

McCune  well  near  West  Point, 

record  of 76-77 

McMenarny  Brothers,  record  of 

well  of 73-74 

Macoupin  County,  Illinois,  pro- 
duction of  oil  in 54 

Madison  County,  Illinois,  St. 
Louis-Ste.  Genevieve  forma- 
tions in 42,  43 

Maquoketa  shale,  deposition  of . .      51 

description  of 22-24 

distribution  of 22-24 

elevation  of 8-13 

occurrence  of  Lingulas  in 23 

production  of  oil  in  sand  lenses 

at  top  of 54 

tilting  of 51 

oil  possibilities  of 63 

Marion  County,  Missouri,  anti- 
clinal fold  in 45 

Burlington  -  Keokuk  limestone 

in 39 

Devonian  outcrops  in 29,  30 


PAGE 

Hannibal  shale  in 35-36 

Louisiana  limestone  in 34 

oil  possibilities  in 59,  60,  63 

Ordovician  rocks  in 16 

Pennsylvanian  system  in 43 

Quaternary  system  in 44 

record  of  wells  drilled  in 68-70 

Sweetland  Creek  shale  in 33 

topographic  maps  of 7 

Meppin,  Devonian  limestone  near     31 
Meramec  series,  description  of . .  39-43 

distribution  of 39-40 

Meramec  strata,   outcrops  of  in 

Mississippi  Valley  area 58 

Meyer,  A.  H.,  work  of 5,  6 

Migration  of  oil 55 

Mill  Creek,  St.  Peter  formations 

in 18 

Mineola  limestone,  description  of.     29 
Mississippi  River,  formations  in 

section  along 7 

Mississippi  River  bluff,  exposures 

of  Kimmswick  limestone  in.      21 
Jefferson    City    formations    in 

traverses  along 16 

Mississippi     River     Commission, 

topographic  maps  of 7 

Mississippi  Valley  area,  deforma- 
tion of  strata  in 60 

geologic  history  of 50-53 

oil  possibilities  of .  63-64 

section  of  strata  in 15 

stratigraphy  of 15-44 

Mississippian     period,     deforma- 
tion during .  .  , 52 

Mississippian  strata,   production 

of  oil  from 54-58 

Mississippian  system,  description 

of 32-43 

Missouri,  record  of  wells  in ...  .  65-74 
Missouri    Condensed   Milk    Fac- 
tory, well  of 65-66 

Mohr,  C.  H.,  record  of  well  of .  .  .  69-70 
Monroe  County,  Illinois,  produc- 
tion of  oil  in 54 

Monroe    County,    Missouri,    ab- 
sence of  Maquoketa  shale  in .      22 

record  of  well  drilled  in 70-71 

Morgan  County,  Illinois,  produc- 
tion of  oil  in 54 

Moscow    Mills,    record    of    well 

drilled  at 67-68 


84 


INDEX 


N  PAGE 

Nauvoo,  description  of  fold  near.  50 
Nelsonville,  record  of  well  near. 69-70 
New  London,  Devonian  limestone 

outcrop  near 30 

Kimmswick  limestone  near..  .  .      21 

Lincoln  fold  near 48 

Noix  oolite  near 25 

Sweetland  Creek  shale  near ...     33 
Niagaran  dolomite,  oil  and  gas  in     58 
Niota,  oil-bearing  geodes  near.  . .     58 
Warsaw-Spergen  formation  ex- 
posed in  quarry  near 40 

Noix  oolite,  description  of. 23,  24-26 

distribution  of 25-26 

North  River,  Devonian  outcrops 

in 30 

Nutwood,     Devonian    limestone 

near 31,  32 

Louisiana  limestone  in 35 

O 

Oil    accumulation,    principles    of 

oil 55,  56-58 

migration  of., .55-56 

origin  of 55 

possibilities  in  Mississippi  Val- 
ley area 54-64 

previous  exploration  for 54 

Ordovician  formations  in: 

Marion  County,  Missouri 16 

Mississippi  Valley  area 16-24 

oil  in 58 

Osage  series,  description  of. 38-39,  58 
distribution  of 38-39 

Outcrops,  location  and  elevation 

of . 8-14 

Ozark  region,  geologic  history  of.      51 
strata  in 15 

P 

Palmyra,  record  of  well  at 68-69 

Pennsylvanian  strata,  description 

of 43-44 

distribution  of 43-44,  47 

production  of  oil  from 54,  58 

Pennsylvanian   period,    deforma- 
tion during 50 

Perry,  record  of  well  at 73 

Petroleum.     See  oil. 
Pike  County,  Illinois,  Burlington- 
Keokuk  formation  in 38 

Lincoln  fold  in 48 

Meramec  series  in 40 


PAGE 

oil  possibilities  in 59 

Pennsylvanian  system  in.  ... .  44 
Pittsfield-Hadley  anticline  in.46,  64 
production  of   oil   and  gas  in 

54,  57-58 

record  of  well  in 78 

sand  lenses  of  Maquoketa  in .  .      64 

Silurian  formations  in 62 

Sweetland  Creek  shale  in . . .  34,  62 

topographic  maps  for 7 

Warsaw-Spergen  formations  in     41 
Pike   County,  Missouri,   absence 

of  Noix  oolite  in 25 

anticlinal  fold  in. 45 

Burlington-Keokuk     limestone 

in 38-39 

Chouteau  limestone  in 37 

determinations  of  elevations  in       7 

Devonian  outcrops  in 29-31 

Hannibal  shale  in 36 

Kimmswick  limestone  in 21 

Lincoln  fold  in 63 

Louisiana  limestone  in 35 

Maquoketa  shale  in 22,  23 

oil  possibilities  in 59,  63 

Osage  series  in 38-39 

outcrops  in 15 

Plattin  limestone  in 20 

record  of  wells  drilled  in 71-72 

Quaternary  system  in 44 

Silurian  outcrops  in 24 

structures  favorable  to  oil  ac- 
cumulation in 60 

Sweetland  Creek  shale  in 33 

topographic  maps  of 7 

Pittsfield,  Pittsfield-Hadley  anti- 
cline near 46 

record  of  Ducey  well  near 78 

Pittsfield-Hadley     anticline,     de- 
scription of 46,  49 

oil     and    gas     possibilities     of 

54,  59,  62,  63-64 

possible  horizons  in 58-59 

structures  favorable  to  oil  ac- 
cumulation in 60 

Plattin  limestone,  description  of 

20-21,  22 

distribution  of 20-21,  47 

elevation  of 11-13 

oil  bearing  shale  in 58 

Pleasant  Hill,  Sexton  Creek  lime- 
stone near 27 

Sweetland  Creek  shale  near ...      62 


INDEX 


85 


PAGE 

Popel-Giller    Drilling    Company, 

record  of  well  of 76 

Prairie   Oil   and   Gas   Company, 

well  of 67-68 

Pressure,  effect  of  in  migration  of 

oil 55-56 

Q 

Quaternary  system,  description  of  44 

Quincy,  absence  of  Devonian  near  29 

Pittsfield-Hadley  anticline  near  46 

record  of  Hubbard  well  drilled 

in ." 74 

R 

Ralls    County,    Missouri,     anti- 
clinal fold  in 45 

Burlington  -  Keokuk  limestone 

in 39 

Devonian  limestone  in.  22,  29,  31,  32 

Hannibal  shale  in 35-36 

Joachim  dolomite  in 19-20 

Kimmswick  ("Trenton")  lime- 
stone in 21,  22,  60 

Lincoln  fold  in 63 

Louisiana  limestone  in 34-35 

Maquoketa  shale  in 22 

Noix  oolite  in 25-26 

oil  possibilities  in 59,  61-62,  63 

Osage  series  in 38-39 

outcrops  in 15 

Plattin  limestone  in 20 

Quaternary  system  in 44 

record  of  well  in 72-73 

Silurian  outcrops  in 24 

St.  Peter  formations  in 18 

structures  favorable  to  oil  ac- 
cumulation in 60 

Sweetland  Creek  shale  in.  33,  62,  64 
Receptaculites  in  Kimmswick  lime- 
stone, occurrence  of 22 

Recommendations  for  drilling  in 

Mississippi  Valley  area ....  63-64 
Rockport,  outcrop  of  Sweetland 

Creek  shale  near 34 

Rosedale,  Sexton  Creek  limestone 

near 27 

S 
Sandy  Creek,  Jefferson  City  for- 

.     mations  in 16 

St.  Peter  formations  in 18 

Joachim  dolomite  along 19 


PAGE 

Savage,  T.  E.,  assistance  of 6 

Saverton,   outcrop   of   Sweetland 

Creek  shale  near 33 

Scotland   County,   Missouri,   ab- 
sence of  Maquoketa  shale  in     22 
Sees  Creek,  Devonian  outcrops  in     30 

Louisiana  limestone  in 34 

Sweetland  Creek  shale  in 33 

Sexton  Creek  limestone,  descrip- 
tion of ". 27-28 

distribution  of 27-28 

Shiel,  Devonian  outcrops  near. .  .      30 
Silver,  R.  D.,  record  of  well  of. . .     73 
Silex,  Burlington-Chouteau  lime- 
stone   exposed    three    miles 

northeast  of 40 

Silurian  formations,  at,  in  or  near: 

Adams  County,  Illinois 62 

Lincoln  County,  Missouri. .  .      24 

Pike  County,  Missouri 24 

Ralls  County,  Missouri 24 

description  of 24-28 

elevation  of 8-10 

oil  possibilities  of 58,  62 

reservoirs  in 61 

sand  lenses  in 61 

Silurian  period,  deposition  of  for- 
mations during 51-52 

Snyder  Creek  shale,  absence  of  in 

Mississippi  Valley  area 29 

Southern    Lincoln    County    syn- 

cline,  description  of 49-50 

South  River,  Louisiana  limestone 

in 34 

Spanish  lake,  Ste.  Genevieve-St. 
Louis  limestone  in  old  quarry 

near 41 

Spaulding,  description  of  Lincoln 

fold  near 48 

Joachim  dolomite  near 20 

Staunton,  production  of  oil  near.      54 
St.  Charles  County,  Missouri,  ab- 
sence of  Maquoketa  shale  in.      22 
Burlington  -  Keokuk  limestone 

in 39 

Chouteau  limestone  in 37 

Fern  Glen  formation  in 38 

Hannibal  shale  in 36 

Kimmswick    "Trenton"    lime- 
stone in 21,  60 

Meramec  series  in 40 

Osage  series  in 38-39 

Pennsylvanian  system  in  ....  .      43 


86 


INDEX 


PAGE 

Quaternary  system  in 44 

record  of  wells  in 73-74 

syncline  in 50 

topographic  maps  for 7 

Warsaw-Spergen  formations  in.     41 

St.  Francisville,  Warsaw-Spergen 

formation  near 41 

Ste.  Genevieve  County,  Missouri, 

St.  Peter  formations  in 17 

Ste.  Genevieve  formations,  See 
St.  Louis-Ste.  Genevieve  for- 
mations. 

St.  Louis  limestone,  elevation  of. 8-14 
outcrops  of  near  Grafton.  .  .  .41,  47 

St.  Louis-Ste.  Genevieve  forma- 
tions, description  of .41-43 

distribution  of 41-43 

outcrop  near  Alton 42,  43 

St.     Peter    formations,     artesian 

wells  in 17-18 

description  of 17-18 

distribution  of 17-18 

elevation  of 9-12 

lack  of  oil  in 16 

thickness  of 18 

St.  Peters,  record  of  well  near ...      73 

Stratigraphy  of  Mississippi  Val- 
ley area 15-44,  61-64 

Stronghurst,  well  drilled  near.  .  .      62 

Structural  features  in  Mississippi 

Valley  area 45-50 

Structural  geology  of  Mississippi 

Valley  area 45-53 

Structure,  method  of  presentation 

of 7,45 

Sweetland  Creek  (Grassy  Creek) 

shale,  correlation  of : 28 

description  of 33-34 

distribution  of 33-34,  62 

occurrence  of 23 

oil  and  gas  in 57,  58,  61,  63,  64 


T  PAGE 

Tertiary  system,  description  of .  .      44 
Traverses  along  bluffs  of  Missis- 
sippi River 6 

"Trenton"     (Kimmswick)    lime- 
stone, deformation  of. 60 

oil  and  gas  in .  .51,  54,  58 

wells  penetrating 7 

See  also  Kimmswick  ("Trenton"). 

Troy,  syncline  near 46,  50 

Turkey  Creek,  occurrence  of  Noix 

oolite  in 25 

V 

Vermicular    sandstone,     descrip- 
tion of.  ....  .( 35-36 

W 

Wapsipinicon  limestone,  correla- 
tion of 28 

Warren    County,    Missouri,    ab- 
sence of  Maquoketa  shale  in.      22 
Warsaw,  description  of  Warsaw- 
Spergen  formation  near .  .  .  40-41 

description  of  fold  near 50 

geode  bed  near 40 

oil  possibilities  at 62 

record  of  well  drilled  at 76 

Warsaw-Spergen    formation,    de- 
scription of 40-41 

distribution  of 40-41 

elevation  of 8-14 

Waterloo,  production  of  oil  near.      54 

Weller,  Stuart,  assistance  of 6 

Wells  drilled  in  Mississippi  Valley 

area 65-78 

Western  Adams  County  terrace, 

description  of 49 

West   Point,   record   of   McCune 

well  near 76-77 

St.  Peter  outcrops  near 18 

West    Point    Landing,    Joachim 

dolomite  in  quarry  near ....      19 
Plattin  limestone  outcrops  near     20 
Winfield,   description  of   Lincoln 

fold  near 47 

observations  near 6 


mm 

wMw 


mm 


